Yes, I had the PSR-500 as well...it wasn't in the same league as the 510...it didn't have as many style parts (it had only drums, bass and three other parts), and it would not read bass inversion (on bass) chords....it did have some great AWM sounds, and I remember one of the styles, New Age, was excellent....I used it to do a radio ad.

The PSR-1700 was quite a bit like the 510, but added the disk drive instead of using the 4 page/panel setups...I think a lot of the styles were very similar.

It was with those products that Yamaha finally started catching up to Roland's awesome (for the time) E-series.

Ian