If the recast penalty was for white and black magic only, people would have bitched about RDM soloing being broken.
People really piss me off, first they bitched about Composure being a piece of shit, now they're either saying it's amazing or bitching about the recast penalty. It still would have been good if the recast penalty was 100%. It's not like you cast Refresh/Haste on yourself twice in a row when soloing.
People would have bitched about RDM being able to get 15 melee accuracy while soloing without messing up utsu recast timers? Really?
Everyone thats not a RDM yes.
You can get the haste/refresh/phalanxy/enspell duration bonus the way the composure is now already. The only thing you can't really make use of is the accuracy bonus.