Played some Sins of a Solar Empire: Rebellion to see how it compares to Stellaris (needed my memory jogged). I have to say Sins seems dumbed down by comparison, especially with how planet development has no overarching cost like Stallaris does with food and power credits. For better or worse, Sins is focused on galactic expansion and combat over micromanagement of the empire. Sins can also quickly devolve into a stalemate because of the capital ship and unit caps.
Sins and Stellaris are so different it's hard to truly compare them IMHO, but you did a good job with sharing your perspective on it, I appreciate that! I mean ya they're both 4X, but Sins is more focused on RTS combat and is really more 4X-lite than anything...Ironclad would probably even admit their focus is on the eXterminate aspect.
Where Sins clearly is targeted and succeeds is combat...yes it's empire development/management-lite, very much so, and I wish it had more complexity to it (even something like what Dawn of Andromeda offered would be perfect here). Even with the E4X mod, which does help with research and some further management development, it can't make up for the intentional design implementations that Ironclad put in. Great game overall for RTS fans to ease into the 4X genre IMHO or just flat out fun for sci-fi space combat with some light empire development.
Stellaris is more Grand Strategy much like their other big titles, and not quite direct 4X territory..but close enough. Focusing more on the empire development... just a shame the game slogs on and gets boring, and then the combat...well I have nothing good to day about it here. I'd prefer GalCiv3's instanced hands-off combat to what Stellaris offers...it just doesn't do it for me. But for most folks that enjoy this title, it fits the bill. Don't get me wrong, Stellaris has a lot to offer...and I initially enjoyed post-2.0...but I've yet to get through a game before I get bored and go back to GC3, Polaris Sector, etc. games that I personally enjoy more.
Where both games succeed and shine is mod support, both have some amazing mods. I love the E4X + Star Wars Interregnum for Sins Rebellion...good fun if you like SW. There's plenty of others in different themes as well. There's some solid Stellaris mods, but I really haven't kept up on it since I put the game down shortly after 2.0 dropped.
I've been playing Distant Worlds Universe, and I gotta say between that and GalCiv3 lately my 4X fix has been really good overall. I mean combat isn't great in either of them, but I prefer it them overall to Stellaris. GalCiv3, being turn-based isn't in my preferred genre, but I'll be damned if the game is good enough that I truly enjoy it...and honestly TBS has worked well because I rarely have more than an hour of uninterrupted gaming time...and really it's probably closer to 15-minute intervals between work and kids lol! That could be the cause of be enjoying GC3 so much. But I really do enjoy it and almost every turn feels important, which I applaud Stardock on accomplishing. I feel GalCiv3 has really hit its stride, worth picking up GC3 Gold (includes Crusade) and Intrigue DLC if folks are interested in 4X that is like Civ in space IMHO. I'm not CIV player really...but GC3 is near the top of my most played in 2018 list.