It's too loose. Compared to the Wii and the 360, the PS3 has the loosest analog sticks in the business. Maybe some of the older games had some sort of auto-assist turned on or something but, of all of the PS3 games I've played (and possibly all of the PS2/PS1 games), this game is the hardest to put on target. It's not a game breaker and you get used to it, though.
My only problem was the part where you had to snipe some bad guys before they sniped you. You only had a few seconds to get on target from behind cover, fire a shot, and hide again. I've been using analog since the beginning (N64/PS1) and I know I don't suck but I kept getting shot or missing my target.
My theory: A lot of games let you use aim-assist in the single player game but turn such assists off during the multi-player. I think U3's developers just use the same aiming mode during both (auto-aim turned off).
