Well, this also relates to an earlier post. I had a chance to sell the PA3X, after two plus years, for the same price I paid for it new. Also, the PA900 is much lighter, has a bigger screen, speakers, and sounds so close that I can't tell a difference.
I did lose some controls that I wish I had, such as Touch Strip (Ribbon Controller), three banks of programmable sliders, dedicated buttons for changing lead sounds and ability to use the FC5 foot controller. All in all, I used the PA3X for all that time at a net cost of zero $! I bought the 900 used.