Hi,
I think for full pianist mode the 76 keys would be great. Guessing a lot of people don’t play in pianist mode.

61 keys for arranger mode if one plays full chords i tend to think is a is a must.

Tried the pa800 with its broken f1 key, would have thought I’d easily be able to play it considering the key is so low down. Wrong, without trying to relearn some of the chord inversions I use, I kept hitting it.