I'm a few hours in, though never played the previous two games. I went in hoping for a more modern-age DOS 2, and haven't been disappointed for the most part.
One thing I'm sure will annoy people is that you cannot really.. ambush enemies, as far as I can tell. You often get sucked into combat, and then (at least in my case) you get to watch all of the enemies shoot at your squad that's out of cover and unprepared. Partly due to the fact that the XCOM-like cover system isn't really usable unless you're in combat. I think crouching might put it into play, but it's hard to tell.
I've heard co-op has some issues, sadly. Haven't tried it.