FrankTrollman at [unixtime wrote:1082307362[/unixtime]]Gestalt underlines the fact that classes which don't give you an actual new and interesting ability every single level are craptastic.
Bad class design is probably the problem here, I agree.
Though it's not so much empty levels, it's the fact that I'd rather take the barbarian class abilities of the 1st-5th level barbarian than the class abilities of the 10th-15th level barbarian, and that sucks. Barbarian and fighter need to offer you stuff worth paying for.