Too subjective. Ketron has had several revolutionary releases, including real drums and real guitars. Yamaha has SA voices, but little else really revolutionary.
The Guitar Mode was a good idea but poorly implemented, imo. Ketron's Riffs would be revolutionary if they could be User Programmed, sort of like Roland's real-time Chord Sequencer was.
I don't know if you can call touch screens revolutionary; I can take 'em or leave 'em.
Tremendous strides have been made in on-board vocal harmonizers by everybody except Yamaha, and the T4 claims to have addressed that finally.
Far from revolutionary is the tendency from all the big companies to use outdated computer technology, I suppose in order to save a few bucks. Ketron just now dropped floppy disks, and Roland still haven't, if indeed they are still a player in the totl market.
AJ, I hope you are gathering ideas for future updates!!
DonM