I thought the demo was really good. I will agree that the cover system isn't very good. You can't even pull back on the analog stick to detach, but at least you can go around corners by pressing X. The reticule being towards the top of the screen is annoying for me since most games have it at the center or bottom (like Halo); I feel like I'm not seeing enough because of it. Though, The act of shooting guns feels great. The shotgun blowing off bits of wall while also taking down a guy in one shot. I thought driving felt great on both normal and simulation. Actually, the punching combat is really good; I'm surprised considering how little you get into fist fights in these games.
My problem with the shooting is more that it just feels like other games. They got rid of a lot of the more 'realistic' parts from the first game. Things like reloading makes you lose the rest of your clip, only being able to carry one large weapon, and enemies that also have a finite amount of ammo (this might still be in the game and I haven't noticed it). I don't think others would agree.
oh, and the wanted system is so good. First, you can just bribe cops for small crimes if you have the money, so you don't get into a big scuffle because of a minor incident. The way it seems to work is based on cops seeing you, and that fills up a bar. It's not like a stupid giant circle that makes the entire area a danger zone. At one point I just ran behind some houses and chilled out a while; after that they were still looking for me based on my clothing, which you could change at your house or another location. If they were chasing you while you were in a car, they start looking for your car, so you can just get out and switch cars and they'll lose it. It's awesome that it isn't just driving really fast to leave a circle.