I'd argue they are above the curve, but not OP. Like I've said before, had one in a party for a two year campaign, she never outshone the insane antics of the other party members. (Allowing a monk/druid to keep their monk abilities while beastshaped, that was OP and a mistake I'll not allow again)
It's only the early levels I feel are too strong (way to steal the Assassin's whole shtick before level 17, and two levels early at that), but unfortunately, they are also the most accessible levels.