Gonna go out on a limb and say most likely all of them. But they get better at 11 too... and 12 and so on.
I'm sure there's key things locked behind a couple talent points tho, so I guess I may be mistaken. For me personally, resto shammy is the best dungeon solo I've made so far (at 15) and getting that insta heal at 11 is pretty huge. Not trying to bash on 10, just not sure why people are still hung up on a number beyond the forum classification.
That said, I bet 10 kick some serious ass with full epics... but so will any level with how over-cooked epics are. Every time i try to make a 10 now I just see "better" just a few talents away. Didnt used to be that way, maybe it'll come back around.