Hi Tim,
As you know I recently purchased a Korg Pa588. I considered the Pa2X Pro or even the Pa800 but I just didn't want to compromise by not having a full 88 note weighted action. I already have a good 61 note arranger that I have used several times but couldn't stand playing the non-weighted action at least when playing legit piano pieces. As for playing other sounds like organ of solo instruments i.e. trumpet, flute, etc. I don't find the weighted action to be a hindrance at all but maybe that's because I am used to weighted actions.
Regarding the additional features of the Pa2X/800; You have to ask yourself what you really need.
I don't care about sampling, the factory presets are plenty good and the synth engine is very powerful in the way of editing/creating new sounds using the vast assortment of waveforms included in ROM. I suppose if there was some specific waveforms you needed that weren't already in ROM, then the ability to sample would be useful, but for those with programming chops, there is a lot of potential for creating what you need right inside the instrument.
I do kind of miss having a harmonizer or at least a mic input with effects, although my amp has a mic input with a good assortment of digital effects so not a big deal.
The one thing that I would kind of like to have is the ability to record/playback audio files. But since I have an M-Audio MicroTrack it isn't any trouble to record the audio into that and then transfer it to my PC to burn to CD or whatever. And for audio playback, it is easy to connect my iPod to the audio inputs of the Pa588 for break music or to play along with mp3 files. So the lack of the ability built into the Pa588 still is not that big of a deal.
The other thing that would be nice is to have more than one assignable pedal input for fills, selecting variations, etc. But There are a number of MIDI footswitches available that can do the job via MIDI program changes on the Control Channel. Then again, I kick pedals for bass most of the time so my left foot is already busy holding down the bass and my right foot is normally on the sustain pedal. The button layout for fills and variations are smartly located so triggering these by hand isn't cumbersome anyway. So again, not a big deal.
What is a big deal is how good this instrument sounds, how easy it is to operate and how versatile it is. All this talk of DNC sounds, SA2 sounds, etc. personally I just don't see that as all that important. I mean the sounds as they exist in the Pa588 are very good and playable the way they are. The trick is to play the selected sound in the style of the real instrument. It always kills me when I hear someone using a monophonic instrument like sax or trumpet or whatever play chords; it immediately takes away any realism that otherwise might exist. Or playing an organ or guitar sound while using the sustain pedal. Having the extra velocity samples, or fancy algorithms to automatically select from an assortment or articulation waveforms is cool, but if the player doesn't impart the playing technique of the actual instrument, the extra stuff is worthless.
Enough of my 2 cents.

Best Regards,
Dave
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Wm. David McMahan
LearnMyKeyboard
JazzItUp Band
The Modulators [This message has been edited by WDMcM (edited 08-27-2009).]