So, am I to understand that you created a drum track on GB on the iPad, plugged your iPad into your keyboard but you're playing the keyboard?
Am I getting that correct?
Correct. The keyboard is just used as a controller. No audio/sounds are coming from the keyboard. All audio is coming from the iPad. I wouldn't sell your Motif just yet. I think it's almost there. The polyphony is low (especially for Gospel musicians). However, who knows when those developers will create an app that can be used as a decent piano sound with a good amount of polyphony and low latency.
Speaking of which last night in rehearsal our bass player didn't show up, and one of our keyboards was going to play key bass, however, the only other keyboard we had was a Yamaha DX7...a little dated to say the least. I pulled up my Korg iMS-20 app and he started playing key bass. For those who maybe are not that familiar with the Korg MS-20, the synths, leads, and synth basses sound very similar to a Korg Triton. Actually, it's the Korg Triton that sounds similar to the Korg MS-20.