Feels good so far.

Been using "old" firefox on a Mac with Desktop monitor and after upgrading to this version (57.0) the memory footprint definitely decreased.
IMO, so far, so good.

It's pretty good indeed. You can indeed sense the smoothness, especially on scripts and content heavy pages like Twitter. They could do a bit better job with the theme and how menus are organized, but I'm just glad they sacked the god awful Chrome theme and gained back their own identity.

There is just one problem. I sacked Firefox few months ago because of the problems I had with it and started using Opera. And I fell in love with it. I don't think speed alone is enough to gain me back. Opera's integrated AdBlocker, integrated mouse gestures, out of the box last tab close button that doesn't close the whole browser, on the fly unit conversion, video popout and overall smoothness and effortless use is just something I'm not willing to trade. And the fact that on mobile devices, Opera browser is nearly impossible to match, I think I'm staying with Opera regardless. Firefox, while it can gain with addons, they just aren't on the level of quality Opera's integrated features have. And syncing all that to my mobile phone on rather clumsy mobile version of Firefox, I don't know. I never thought Opera would come to this point after they sacked their old ways after Opera 12, but those bloody Scandinavians did it. Opera 49 is a fierce competition on the browser market and it's just better than everyone else at the moment.

Still, give it a try, Firefox is way better than god awful Chrome. Or super fast but rather limited functionality wise Edge.

I've run sunspider js benchmark:

TEST COMPARISON FROM TO DETAILS

===============================================================================

** TOTAL **: *1.44x as slow* 162.7ms +/- 7.2% 234.2ms +/- 2.6% significant

===============================================================================

3d: *1.51x as slow* 30.4ms +/- 7.8% 45.9ms +/- 11.9% significant
cube: ?? 15.1ms +/- 18.2% 20.6ms +/- 28.1% not conclusive: might be *1.36x as slow*
morph: *1.98x as slow* 4.4ms +/- 8.4% 8.7ms +/- 6.8% significant
raytrace: *1.52x as slow* 10.9ms +/- 5.7% 16.6ms +/- 8.9% significant

access: *2.29x as slow* 11.4ms +/- 4.4% 26.1ms +/- 0.9% significant
binary-trees: *1.43x as slow* 2.1ms +/- 10.8% 3.0ms +/- 0.0% significant
fannkuch: *2.40x as slow* 5.0ms +/- 0.0% 12.0ms +/- 0.0% significant
nbody: *2.00x as slow* 2.0ms +/- 0.0% 4.0ms +/- 0.0% significant
nsieve: *3.09x as slow* 2.3ms +/- 15.0% 7.1ms +/- 3.2% significant

bitops: *1.65x as slow* 7.1ms +/- 7.4% 11.7ms +/- 3.0% significant
3bit-bits-in-byte: *2.50x as slow* 0.8ms +/- 37.7% 2.0ms +/- 0.0% significant
bits-in-byte: *2.18x as slow* 1.7ms +/- 20.3% 3.7ms +/- 9.3% significant
bitwise-and: ?? 1.7ms +/- 20.3% 2.0ms +/- 0.0% not conclusive: might be *1.176x as slow*
nsieve-bits: *1.38x as slow* 2.9ms +/- 7.8% 4.0ms +/- 0.0% significant

controlflow: *1.82x as slow* 1.7ms +/- 20.3% 3.1ms +/- 7.3% significant
recursive: *1.82x as slow* 1.7ms +/- 20.3% 3.1ms +/- 7.3% significant

crypto: *1.66x as slow* 16.5ms +/- 5.9% 27.4ms +/- 2.5% significant
aes: *1.140x as slow* 10.0ms +/- 8.3% 11.4ms +/- 6.1% significant
md5: *2.06x as slow* 3.4ms +/- 10.9% 7.0ms +/- 0.0% significant
sha1: *2.90x as slow* 3.1ms +/- 7.3% 9.0ms +/- 0.0% significant

date: *1.136x as slow* 19.1ms +/- 2.1% 21.7ms +/- 1.6% significant
format-tofte: *1.46x as slow* 8.7ms +/- 4.0% 12.7ms +/- 2.7% significant
format-xparb: 1.156x as fast 10.4ms +/- 3.5% 9.0ms +/- 0.0% significant

math: *3.19x as slow* 8.1ms +/- 5.0% 25.8ms +/- 2.5% significant
cordic: *2.67x as slow* 2.1ms +/- 10.8% 5.6ms +/- 10.8% significant
partial-sums: *3.33x as slow* 4.8ms +/- 6.3% 16.0ms +/- 0.0% significant
spectral-norm: *3.50x as slow* 1.2ms +/- 25.1% 4.2ms +/- 10.8% significant

regexp: 1.46x as fast 7.3ms +/- 4.7% 5.0ms +/- 0.0% significant
dna: 1.46x as fast 7.3ms +/- 4.7% 5.0ms +/- 0.0% significant

string: ?? 61.1ms +/- 15.0% 67.5ms +/- 0.9% not conclusive: might be *1.105x as slow*
base64: *1.96x as slow* 5.6ms +/- 33.6% 11.0ms +/- 0.0% significant
fasta: *2.06x as slow* 6.8ms +/- 6.6% 14.0ms +/- 0.0% significant
tagcloud: *1.38x as slow* 13.6ms +/- 14.7% 18.7ms +/- 3.6% significant
unpack-code: 1.89x as fast 28.4ms +/- 24.9% 15.0ms +/- 0.0% significant
validate-input: *1.31x as slow* 6.7ms +/- 7.2% 8.8ms +/- 3.4% significant

first column is new firefox and second is latest chrome. Chrome is significantly slower in every test except with regular expressions, dna and unpack code. String management is on par.
I want to see this javascript engine in node.js ... shouldn't take long ... any time now

I have Waterfox as my main browser.

The FF Quantum update definitely feels snappy.

A good test opening up hotmail/gmail/youtube.

Long time Firefox user. Wow, the new version is so much faster, I'm impressed.

Not used Firefox for years but this release has piqued my interest, I must say first impressions are very good, and it is indeed very snappy.

Bravo Mozilla.

Maybe now the chrome fanboys finally wake up and stop using a crappy browser that eats ram left and right? Firefox was already better than Chrome, now is even an insult comparing it to chrome. Or just go on the store and buy 8gb ram to make chrome usable. Your decision.

Wow. It's so fast.

I have been on the quantum beta for a while - it is blisteringly fast. Did not think I would notice much but WHOA... this is a very fast browser. Makes for a new internet experience.

Looks good. just need more cores.

Been using the beta for about a month now. Uhmm... works fast, flash is leaking but.. its flash.

JhelmsI have been on the quantum beta for a while - it is blisteringly fast. Did not think I would notice much but WHOA... this is a very fast browser. Makes for a new internet experience.

I'm always on the beta channel ;)
Performance was never an issue for me, but yes, this does feel snappier. Now if only extensions will migrate...

I tried it and it sure is a major upgrade, and looks a lot sleeker.

Don't like the dark inactive tabs though, too distracting

My only concern is if all my add-ons will still work. I don't have very many installed... just two that I can't live without. One to download videos from YouTube and another one to download videos from sites like Lynda

bugNow if only extensions will migrate...

GoFigureItOutMy only concern is if all my add-ons will still work.

That's my biggest hold-back. Am not letting go of the plugins that provide security and makes using the net functional in a level that meets my needs.

lexluthermiesterThat's my biggest hold-back. Am not letting go of the plugins that provide security and makes using the net functional in a level that meets my needs.

Ad blockers have been updated (and many others). The only thing I use that isn't migrated yet is NoScript.
Then again, I only use a handful of plugins on a daily basis, ymmv.

bugAd blockers have been updated (and many others). The only thing I use that isn't migrated yet is NoScript.
Then again, I only use a handful of plugins on a daily basis, ymmv.

NoScript is a big one for me too. Chatzilla, cookie management, the list goes on. What's interesting is that Mozilla seems to be actively reaching out to the plugin devs to help them transition. So likewise it seems likely that most plugins will be made compatible. So we wait. The ESR build will be supported for some time yet, so there's time.

lexluthermiesterNoScript is a big one for me too. Chatzilla, cookie management, the list goes on. What's interesting is that Mozilla seems to be actively reaching out to the plugin devs to help them transition. So likewise it seems likely that most plugins will be made compatible. So we wait. The ESR build will be supported for some time yet, so there's time.

Mozilla has been reaching out for over a year now. If it's now well on its way of being ported, chances are that plugin is abandoned. Luckily NoScript is not abandoned, but they still haven't figured out how to let it kick in before the page loads.

And about cookies, the only management I use is to not accept 3rd party cookies and set cookies to expire after 10 days (prevents piling up).
The UI for setting cookies to expire is long gone, but you can still set network.cookie.lifetimePolicy=3 and network.cookie.lifetime.days=<whatever_you're_comfortable_with> <- no plugins required, the only side effect that I'm aware of is that I need to log in again after 10 days. But even that is a plus in my book.

bugLuckily NoScript is not abandoned, but they still haven't figured out how to let it kick in before the page loads.

That's a problem many devs seem to be having. The question is, based on the way the page rendering engine now works, is it even possible? It's a deal-breaker if it can't. On that note, the WaterFox devs have made the commitment to continue supporting XUL based plugins for the foreseeable future. Been playing around with it and have yet to see any problems. I'm actually liking the way it renders pages a bit better. Might just convert over if these plugin problems can't be worked out.

bugAnd about cookies, the only management I use is to not accept 3rd party cookies and set cookies to expire after 10 days (prevents piling up).
The UI for setting cookies to expire is long gone, but you can still set network.cookie.lifetimePolicy=3 and network.cookie.lifetime.days=<whatever_you're_comfortable_with> <- no plugins required, the only side effect that I'm aware of is that I need to log in again after 10 days. But even that is a plus in my book.

My cookie settings are very different. They are set to accept third party cookies only from sites I visited in that session, and all cookies are deleted after Firefox exits. I also have a plugin that deletes LTSO's so that browsing can not be monitored from session to session.

Apparently Noscript 10 should be ready soon hackademix.net/2017/11/14/double-noscript/.

I feel naked without a script blocker :twitch:.

I'm using No-Script Suite Lite for the time being but I much preferred Noscript.

lexluthermiesterThat's a problem many devs seem to be having. The question is, based on the way the page rendering engine now works, is it even possible? It's a deal-breaker if it can't. On that note, the WaterFox devs have made the commitment to continue supporting XUL based plugins for the foreseeable future. Been playing around with it and have yet to see any problems. I'm actually liking the way it renders pages a bit better. Might just convert over if these plugin problems can't be worked out.

No idea if it's fixable. It's definitely not an easy fix, that's for sure.

lexluthermiesterMy cookie settings are very different. They are set to accept third party cookies only from sites I visited in that session, and all cookies are deleted after Firefox exits. I also have a plugin that deletes LTSO's so that browsing can not be monitored from session to session.

Sounds like you're mimicking private windows.

Oh and I just thought of a downside: this new Firefox absolutely murders CPU when streaming videos (not with youtube, I haven't pinpointed the cause yet).

BeastieApparently Noscript 10 should be ready soon hackademix.net/2017/11/14/double-noscript/.

I feel naked without a script blocker :twitch:.

I'm using No-Script Suite Lite for the time being but I much preferred Noscript.

Nice! Totally with you. NoScript Lite is good on Chrome as well. Not as good as the standard NoScript though.

bugOh and I just thought of a downside: this new Firefox absolutely murders CPU when streaming videos (not with youtube, I haven't pinpointed the cause yet)

Which sites? I tried it out with TwitchTV and it seems to be ok, resource-wise.

Have used Chrome for the last 10 years or so, but it has become less stable over the years and is dead slow sometimes... This new FF seems like a breath of fresh air..