Sorcerer is a pretty powerful class but his healing ability actually isn't good the later you get. At level 9/10 a puny 12 HP per fireball is kind of terrible, really.
Though Sorcerer reams the early game and for normal/hard difficulty dungeons, he's pretty boss. He just doesn't quite have to power to stand amongst the tops like Paladin or Cyddstep Rogue.
Edit: I wouldn't mind seeing Elf at 55-65 conversion point rate.