I would rather not take this too far but I had a Pa800 and a Pa900 side by side in my home for over a month; the Pa800 did sound better to me.
Someone told me the specs say different but I know what I was hearing.
I feel that people do not all hear the same; especially as they get older. So what I heard is what I based my opinion on.
The key feel is without doubt better on the Pa800.
The fill-ins and break would repeat until stopped forming a nice grove. This is not on the Pa900. Some sliders have been turned to nobs. Is that bad? I guess that’s opinion.
In My Humble Opinion, John C.