I have never had much time playing the old XCOM games which is an embarassing confession but I was young and I was much more interested in programming than playing back then, oh well. Not the only game I actually missed out on. But so far I like the game and I would say one of the best games I have bought this year.
I can echo some issues here though. It does have many bugs and it seems to be a hallmark of any Firaxis game to defy proper Q&A methods. One of the most hilarious ones I've encountered yesterday: As I wanted to create a new 'door' with my rocket launcher exposing the nasty commanders holed up within a room. Used the rocket, blew that hole into the wall and apparently the ground as well. All commanders fell to their deaths and I completed my mission (talk about sending them properly to hell).
Which also exhibited one of the glaring bugs I have encountered a few times namely that rockets and grenades tend to send opponents through the grounds and sometimes make the camera stuck in limbo luckily spamming T until camera resets again solves this problem.
Another thing I am agreeing with are the voice-overs. Would have been nice if they actually had their nationality/region had an influence on their responses and talks. It's not exactly that Firaxis is short of resources for that.
Although I really do like the otherwise very atmospheric music they should have offered more but then again, Firaxis game, means soundtracks are either bought or on a very short leash (yes, I am looking at you Civ V: G&K with the Byzantium players getting standard Western-European music).
Overall a top game recommendable for anyone who is actually missing traditional squad tactic games.