For me, it was the improved sounds/voices, which were far more realistic than the prior models. There were a few OS updates that came with the upgrades, but nothing that I could not cope with or learn in a few weeks of exploring the keyboard. I managed to sell every one of the prior models within a few months of purchasing the upgrade. The only reason it took that long was that I wanted to be able to do the same things on the upgrade in the same time frame, before taking the newer board on the road.

Good topic, Diki,

Gary