So I played the shit out of XCom on the Amiga (as UFO: Enemy Unknown), and then played a ton of Terror from the Deep on PC. I was a huge fan of the series back in the day, and still keep them around to replay them once in a while. But man.. People have a real skewed perspective on how good that series actually was.
Unpopular sentiment, probably, but the most fun bits of any XCom game is researching new gear and reading research reports. The geoscape is a random slog, and tactical battles are random slogs. The games get painfully repetitive fast. Much of the satisfaction comes from the tension, and constant sense of danger and risk. But what this really inspires is a save-reload cycle every turn, and in the long run, considering how many battles you get into, boy does that get boring.
I think the absolute worst Firaxis can do must still be better than what XCom actually was back in the day. Don't get me wrong, they are charming and exciting games, but they are not perfect by any stretch of the imagination, no matter how much people want to insist hunkering down outside of a UFO door for turn after turn waiting for the aliens to randomly bumble their way out of it into your field of fire is a tactic, or that repeated terror missions on the other side of the globe when you've put up your first base, killing half your funding, is "part of the game".
People need to relax their nostalgia about this thing. I think of XCom and *feel it in my heart*, but man, mechanically the games are not stellar.