As far as realism and LIVE sound, my personal choices are, in order:
Ketron Audya
Ketron S Series
Roland G and E series
Yamaha Tyros 3

Individual sounds are very subjective. Yamaha has some great guitar and sax voices and the keyboard can add nuances for you.
Ketron excels at natural sounds, particularly drums and bass. Really strong in Country/Western and old-time Rock N Roll.
Roland has many great features and sounds.

I had a stinker of a Korg PA80, so I can't be objective about it. I hated it for lack of styles, hard to use interface, especially when loading styles, and dull sound. I'm sure it's better now with the Os upgrades.

I truly feel for a blind person that Ketron would be well suited, because they have so many dedicated buttons and sliders.

Hope this helps, it's only my opinion after playing these things since they were invented.
DonM www.donmasonmusic.com