PSR 8000 was WAY ahead of it's time. But didn't the styles have only two variations?
It is neat how the Groove thing works; take a style and apply it and you get a whole new style.
Yes only two variations but what I liked was that Var A and Var B were significantly different enough from each other.
Incidentally didn't Yamaha have 4 variations in the keyboards previous to the PSR 8000 such as in the PSR-5700 & PSR6000? I've only ever seen pictures of those so I may be wrong, but it looked like 4 vars.
Another featured I liked about the 8K was the Virtual Arranger, added that extra attractiveness to the styles especially the ballads.