Gen Fu is awesome. Short ranged, short combo, but very solid. I find that if you use Gen Fu, you gotta be good with blocking, countering, and hitting effectively, otherwise he's deadmeat against faster character with wider attack range.
@SoftCabbage exactly, he takes a lot of patience, but when you build momentum and assert dominance in the match, he actually is really fun and rewarding to use. He's like stronger, but close quarter version of Eliot