Normally i skate the classics in a 54mm think they're 101A, i've been skating the "hardline" lately, which i think have a softer inner core, don't really notice any difference to be honest, i've got some classic aircores or some shit to skate next, i had pair before, they feel a bit lighter when you're holding them in your hand but bar that couldnt' tell any difference.
Dunno, just found Spitfires good, i don't really like Blueprint or Cliches wheels, they're to plastically and have some wierd hard thing going on, perfer actually urethane to them