Not because I have one, but I think the PA800 series from the PA80 is quite a jump:

1. Superb Songbook
2. TC Helicon
3. Improved sounds
4. Vastly improved OS

I wanted so bad to take the PA80 live, but the OS was silly and impossible for live play, so I stuck with Yammy.

When the 800 arrived, it was like an entirely new product (IMO) and a live player's dream.