Got it with my graphics card, and hadnt installed it till yesterday.
I wish I'd done it earlier.

I really enjoyed it. The graphics look really nice (even if some npcs are a bit dodgy), animations are great (though lipsynching is way off), gameplay is sound and intuitive. Using mouse 2 to hug the wall is brilliantly simple and excellent for combat, where quick reactions are definitely needed.
The sound design is incredibly immersive, which I find to be a key factor in my enjoyment of games. Sometimes it was actually like I was in a casino under siege.
If the sound design is off in a game, then I feel distanced from it. I find most games these days cant balance the levels of sound corectly, eg the music is barely audible over sfx or visa versa.

If the coming sequel Vegas 2 is anything like this, it's surely on my list of purchases.

have heard good things about the helicopter jumping, door-breaching new Clancy release! must have been a pretty nice card to come bundled with that

Bah vegas is horrible imo.
Had on the 360 easy to complete and the window jumping through is nothing special.