I've had my Lachesis for about 2 weeks now. I purchased it to replace my worn out Copperhead. I'd have to say I'm starting to like this one better them my copperhead in both performance and feel.
Firstly, I'm left handed. So as you are all well aware, there a VERY few GOOD mice out there for left handed gamers. to many of the pro mice are right hand ergo only.
Pro's
1) speed, this mouse is FAST. At a full 4000 DPI it responds almost like it's got ESP. I mean It takes about an inch for a full 360 degree spin in CoD4. My overall wrist movement in FPS games has reduced a lot.
2) Buttons work well with my hand. I have read a lot of the reviews that complain about this mouses fit in the hand. I think this is very subjective as everyone has different sized hands. I have a nice firm hold on the mouse and my thumb is fully able to press the right side buttons without needing to hold the mouse down. I also use the two left side buttons for my DPI setting changes, Since I do not do a LOT of DPI changing I use the two buttons my hand simply will not let me depress due to their placement in regards to my pinky. This does not bother me overmuch as I still have a total of 7 buttons plus the forward and back scroll that I can bind to in game. The two new top buttons just behind the scroll wheel are easy to depress and use while madly dashing around a game map.
3) the configuration tool has more options added in for button configuration. Including some basic per program button configs. Take this feature along with the profiles and you have a mouse you can customize for every game you play. This has made me very happy.
Con's
1) this mouse currently has the minor issue of drifting at low movement rates. You do not notice this when gaming, but in windows the mouse pointer will jump a tad erratically. This is due to the extreme sensitivity of the laser. According to the Razer web site this small issue is being addressed in the next firmware+driver pack that is supposed to be coming out shortly.
2) The super sensitivity takes a bit of getting used to...not really a Con, but for some, if you do not have the patience to practice with it, you may find yourself getting frustrated and simply returning to the lower resolutions. Now the mouse work perfectly at lower resolutions and at 2000 DPI it reacts identically to the copperhead.
In Conclusion, if you have a hand that fits this mouse, there is really nothing nicer to use. (I have a somewhat slender hand with a full length of about 7". My hand is not small by any means, but it is definitely not beefy.) It has a LOT of features and options available for customizing it to your needs. Just be willing to get used to it. try and keep your mind open and your frustration in check, as once you do get the hang of it, it's poetry in motion.
O.
BTW: Regarding the reviewers concern with the feet. The material used is the SAME as that used on the copperhead. It is definitely softer then most, but it has a much nicer glide feel than many mice. As for it's durability, use it on a smoother surfaced mouse pad. I found that with the copperhead the smooth mouse pads almost didn't wear on the feet were the rougher pads tend to. The same experience is showing with the Lachesis as well. I have been playing a LOT over the last couple weeks and there is no noticable wear. I use a Func 1030 Surface (smooth) mouse pad.