Rainbow Six Vegas has it where it counts on every level.
For those who are familiar with both titles, the game is very much like a hybrid of Rainbow Six 3 and Gears of War (which is not to say that they stole the concept of more active cover system, as both games were in development at the same time). The new concept of cover works well at almost all times; problems with it are rare enough to easily be forgivable. And with an excellent single player campaign and an (almost equally good) coop offering, R6: Vegas is a game that should not be missed.
The story does it's part, and is of sufficient quality to feel like more than just some kind of hollow justification for gunning your way through multiple fictional casinos.
Graphically, the visuals are top-notch: well modeled characters and environments covered by very detailed textured are offset by glossy neon lights abound. The sound (in the single player campaign at least) is satisfactory. The music and sound effects properly perform their role, and the voice acting is more than satisfactory. The sound in coop, however, cannot be so highly lauded. No music is available, the story aspects of dialogue are removed almost in their entirety, set aside a few pieces which, now being alone, seem out of place and inappropriate above all else. Also, there is an all but complete lack of ambient noise at times, making it seem more like you’re fighting your way through a casino in space rather than Vegas, though a few sounds here and there can, at times, mitigate that problem.
Overall, the changes made ensure that the Rainbow series is, as of this release, once again in top form. Armed with a comfortable selection of weaponry and grenades, well-honed difficulty levels, and top of the line graphics and sound, Rainbow Six Vegas is an offering for the 360 that is not to be missed.