So I've spent a couple nights playing Driver 3, aka DRIV3R. It has taken a bit of time to get used to the car physics -- in particular, how tightly a car grips when going around a corner.
The game looks great (if you can forgive some pop-up), and the cars (and damage to them) looks fantastic. But the character movement is a bit touchy. Car handling seems quite fine. The missions are kind of a bitch, though. You'll find yourself trying a particular mission over and over. One wrong move and it's off to retry-land. Missions in GTA are much more forgiving. I never had to retry them so much.
The guns are very good, along with gun combat. I wish you could peek/lean around a corner, though. Way too often, I end up moving out from a corner simply to get somebody into my gunsights... BLAM! Down I go. And back to retrying the mission. Sigh.
Vehicles are neat. I've already been in multiple cars and boats. From a demo scene, it looks like motorcycles, too. Oh, and a cop car. With sirens.
The game is very linear so far. From one mission right to the next. I'm not sure where the variety is here. You can certainly "free drive" around the city, but I haven't tried that yet, so I'm not sure what it gives you. Within the missions, there is very little variability. "Follow this guy" or "Go over there and wax some guys." Not a lot of strategy there.
So far, it is nice. The gameplay doesn't beat GTA though. While I still have some more game to go, and might get blown away, I'd highly recommend going for the GTA double pack instead of this one. If you've already done GTA and want some driving/mission gaming, then this game certainly seems fine.