Hal, the Motif and and all workstations are VERY different from Arranger keyboards like the Tyros.

Workstations are not TRUE arrangers in that there are no Intro's, Endings, Breaks, Fills, etc on the drum / bass track. Also, workstations arpeggios really only have 4 parts; bass, drums, some chording and right hand. The arranger has 8 parts of accompanyment.
I would and don't use the Motif on solo gigs; it is just not suited for that task. Karma is kool, but it too is not meant for the arranger player. It is a random beat generator that sort of follows your chording, but doesn't recognize elaborate chord structures.

Do you currently have a workstation? What do you currently play?