OK - this is my second time around with the PA80 (it's actually my THIRD unit)
The new o/s 3 has a marked improvement in a few spots but there are still a few things missing ... Listen up, KORG !
1)Global EQ, or a way to shut OFF the "loudness" contour that is built in. The bass booms too much and the speakers can't handle too much else at the same time (re: vocals)
2)Set up a sequence while a pattern is running. We need to search for "what's next" while we are doing something. This is important ... please try to do this.
3)The selected sound should NOT be cut off if you change from split to full mode. The abrubt cutoff is very unpleasant, and should be avoided.
4)All three right hand sound layers need to be able to transmit on the SAME midi channel. I need to send note values to my harmonizer, but if I choose voice layer two or three - they are sent on different channels than the first layer.
5)EASIER rhythm loads from disk - this is a confusing issue - it's not easy to load new styles .... too complicated as it stands .... needs to be a no-brainer
6)ALL new keyboards with hard disks need a way to search the disk with a ten key type pad - the PA80 lets you call up sequences by a number, but a letter would be much better .... who can remember numbers ?? AND, they change as you add songs to the disk.
7)Needs a better mixer / effects section. It's too hard to decide how to send one effect here, and another there .... it needs a "yamaha-esk" interface.

There are a few more things that erk me, but these are the biggies for now.
The button pushes, and locations is still an issue that Yamaha has perfected - The Korg method is still too clumsey.