Someone who sugguests there's not much difference between a Tryos and a PSR is not making use of the incredible sound of 3 layered voices of horn sections, rich organ sounds and violin and orchestral sections and aftertouch, especially to me on guitar that will become hard to live without once used properly.
If those things are not used, then you have the players who say they sound the same. Which only makes me think how much they are missing either through choice or not knowing it's there or how to make full use of it.
I may have been spoiled after years of playing top of the line home organs.
The PSR's are great kb's, but once hooked on the couple features I mentioned, and really milking those inflections using aftertouch etc, it is a bit of a let down not having those features available.
If those sounds and features aren't important to the player then the PSR should do the trick. But to me, the difference would be sounding great on a PSR, but going WOW everytime you play a Tyros
Best
Scott