My group found the 4e warrior defender/striker types to be incredibly samey outside their class specific mark/bonus damage mechanics. They thought the casters were super samey too, being mostly area/single attacks with ok damage or crap damage and a rider. Except the fighter 'come and get it' that we referred to as the gravity shift fighter spell.
The person who tried bard got pretty pissed. Had taken a bow, implement, and weapon powers by just picking what sounded good off the list. The forced switching and trying to keep up three required item to-hit bonuses just was insane.
Warlord could be pretty unique with the ally attacks. But nobody, not even a first time rpg player with no d&d history at all, could get over the shout healing.