In my opinion, GO is easily the best CS game since 1.6. It's way more fun to play than Source, and doesn't suffer from any of its issues either. Walking no longer feels like floating, the weapon placement is actually where it should be this time around, and Source's gimmicky physics mechanics have been canned completely, and thank fuck for that.
Other pros include the gun animations, which are really satisfying, all the classic maps have been revamped visually, although the layouts are mostly the same, and some long overdue improvements have been made to the buy menu and the score tab, and the way that they work.
There are two major cons to this game, however.
There are a number of visual effects that can't be turned off in-game, and that can hinder your vision on certain maps (most notably the fog on Aztec). There are ways for servers to circumvent that, however, and turn those effects off server-side, so that may not be that big of a problem in the future.
The other major problem with the game is the motherfucking crosshair.
There are two crosshairs that you can choose from: the default one, which looks fine, but that I, and I expect many other players as well, hate the feel of, and there're also the classic one, the one from CS 1.6 and Source. The problem is that the old crosshair looks like absolute garbage in CS:GO's engine. The game has such a stark light and dark contrast, that using a borderless crosshair comprised of a single colour, simply does not work. Depending on the colour you're using, the background will either be too bright or too dark to see the crosshair. Hopefully this will get fixed soon.
All that being said, I'm not sure I'd suggest getting CS:GO on the 360. Maybe I'm subjective, but I really don't think that it's the kind of the game that should be played with a gamepad.