There was a huge change in os between G800 and G70.
G70 through E80 was a piece of cake!
I remember teaching a blind friend the G800...in detail..He amazed me with his ability to operate the G800..
The G-70 wasn't so bad, I had it down pretty quickly, but I don't think it is any easier than Yamaha's.
Fran, I taught several blind people on our more recent, and a few older, Yamaha arranger models....that is also why there was a protest from many visually impaired users when it was suggested the next Tyros go to a touchscreen.
I can't say that it was the reason Tyros5 remained with a regular screen, but apparently it is far easier to use for those with sight problems than a touch screen.
I believe it was discussed briefly here as well.