I only bought the game for MP (same with GRAW1, I don't like squad-based shooters with AI), but I'm liking it so far. Lost Planet had been my main MP fix as of late, so it's hard to go back to it after playing GRAW2; LP's controls are just so slow and clunky. GRAW is like butter.
Still, there are certain things that I really can't believe haven't been improved on from the first game. There's still no stat tracking, even though there are still achievements that call for a certain number of kills recorded, etc. The custom game search is still ridiculously slow, and there's still that annoying "feature" where if you join a game that ends up being full, it boots you all the way back to the menu so that you have to search AGAIN. There still doesn't seem to be control customization/southpaw options, even though I remember that being a pretty big complaint with the first game. I mean, even the menu systems are all basically the same.
To be fair, I do like the non-cheese nightvision, ability to stay in ranked rooms, more weapons, etc. It's just those little things that a sequel usually fixes that are bugging me. Plus, I haven't had any disconnects/headset issues, which ruined the first GRAW for me (I hope I didn't just jinx myself).