I have never liked UE3. I think it mostly looks like garbage. They pulled it off in Bioshock, because it's so dark in that game. Mass Effect makes good use of it. Gears of War does a good job of hiding a lot of its flaws.
But I still have a grudge against UE3. The first PC games that came out on it couldn't even do anti aliasing, and there is just no excuse for that. Anti aliasing is a must have as of about 2004. My opinion--UE3 is easy to develop with and makes it easier to crank out a game.