Danny,

I owned and had both together here in my studio.
Using the same external equipment for sound, they both sounded the same to me.

I am not a gigging musician, but if I were, the Pa900 would be the winner hands down in all respects.

I felt the keys were the same to me.

I had the Pa900 first and it is a really good keyboard with the touch screen being really well integrated with the operating system.

All the things Don mentioned about the Pa3X are right on the mark. I purchased the Pa3X mainly because I wanted the tilt up display, internal hard drive and 76 key.

Bill G