The Korg Triton (which I use to own) has two arpeggiators. Each could be set independently to create a sort of style (much like those in our arranger keyboards). Each arpeggiator affects only a few voices or sounds, and even by combining both of them there is no comparison to the built-in styles on an arranger.

Arpeggiators are used as shortcuts for people that use sequencers. It helps them avoid the tedious task of programming every note of every groove they make. I guess you could say that arpeggiators are "groove" makers. They don't play melodies.

Regards,
Stevizard