The AI in UT III is vastly superior to the AI in Jericho, in Jericho you're lumbered with a team of suicidal chumps who hinder your progress rather than help. The game play is the same ol' walk/shoot/walk/shoot/walk/shoot/walk/shoot, the game mechanics a ripped off from
Star Wars: Republic Commando (although they work so much better in that game as you're not limited to a series of endless boring corridors) and the story is no great shakes.
UT III is an online experience; the single player game is ropey, but online is a whole different matter.
Jericho is on a par with
Genji: Days of the Blade, which puts it neck and neck for the worst PS3 game so far IMO.