Ozzimo,

Fran likes playing on old antique junk (G1000). Maybe he's interested.

Tom

I didn't get to see a 4000, but the 8000 was WAY ahead of its time, and contained many innovations. I could still perform on an 8000 and please the audiences.
It had many features that Yamaha has since discontinued, such as the ability to reassign the positioning of styles and voices on the menu. It also had the Groove feature, the ability to automatically change and save the timing of styles, say from 4/4 to Swing, 6/8 or 2/4, in effect creating totally new styles with the push of a button or two.
This feature was later developed further on the PSR740 to convert all styles with the push of one dedicated Groove button which doubled the number of styles available.
It had the first really useable vocal harmonizer built in to a keyboard.
It was sturdily built yet light in weight.
DonM