I've been reading everything I can about CivIV: Col since it's release.
There appears to be some game issues (mechanics) upon release in this game, but the forums are almost polarized by widely opposing player reviews of the game.
People either love it or hate it, it seems.
Some are saying that it was a rushed release and buggy, while others concede that there are a few issues, but should be easily fixed with a sure to follow patch and that the game is essentially playable now right out of the box.
I'll continue to follow the progress of this game and see what develops after a month or so, or when the latest patch from Firaxis appears.
I think at it's core, it looks to be a wonderfully challenging tbs game requiring more focused attention on micromanagement than say one would use in CivIV (BTS) for example.