Oh, UFO:AI also has a much more sensible ship design, where troops leave it from either side, like a military helicopter, instead of by a ramp at the back. However, a big issue I have is that its got some very complex maps (which is good), but you get less people then in X-COM (I want to say eight or ten) instead of 14, so it is harder to actually cover your back and have a team cover unexplored areas and whatnot.
They did a cool thing with overwatch though. I never could figure out exactly how it worked in X-COM, but in UFO:AI you save a set number of TUs based on the type of fire you want to do. Then if an alien is in your field of vision for more then that number of TUs (eight for snap shot, for example), your troop takes that type of shot.
