Surely sound is a subjective thing....if a keyboard came as it was meant to sound or optimised then why add the ability to tweak in the first place? Probably because what sounds 'optimal' to me won't to you. That's the whole point (unless I am missing something)?
I only know I never bought a keyboard yet I did not have to tweak one way or another to make it sound like I wanted it to. That includes Tyros, G70, 9000Pro, KN 7000 ...heck the list is endless.
Look at when the G70 was released....you could not move here for people saying it sounded bad ..... and now a year or so later I hear nothing but praise here for the G70 piano sound. Did everyones hearing change or maybe updates and tweaks worked the magic?

Being in the market myself atm I am however quite interested in the fact that Don's perception of the PA800 (and that of his audience) is less favourable than most of the reports I have read. I have the utmost respect for Don and I know he knows his gear which is what makes me sit up and take note.
I am leaning toward the PA800 but my local dealer does not stock korg. I will have to have a trip down to Blackpool to have a play with one. I have never had a Korg arranger before (well unless you count an i40m module many moons ago). I did own a Triton for a while though. It is either the PA800, PA1x or I may buy another G70. Having already owned a G70 the korgs are attractive simply because they are the only major brand I have never had.
I did have to smile though at Ian's comment that it should sound killer out of the box..... a bit ironic given that quite a few S900 customers have had to take delivery of two or three boxes before they are happy with their 'killer' machine.
Just an observation.
regards
Tony