You also can "re-program" the STS For Each style (OTS in Yamaha lingo), and in the Korg arrangers, is saved actually on the Factory style unlike the Yamaha that has to be saved as User Style. This allows you to customize your sounds, and also if you change some parameters like EQ, Volume, etc. that would also be saved on the Style, if you wish no to do "Performances"=Registrations.

The Performances are the equivalent to Registrations, and they have a unique feature, the "Lock" (Icon is actually a Lock) that locks ONLY the Tempo, just be careful, because if you change style the Tempo would remain if the Lock is engaged.