My first suggestion would be to get the PA3X, Zuki...that's an easy one, since you have spent a lot of time learning Korg's OS, and you don't want to let all that hard work go to waste. (Also see Stephenm52's post above-you can trust Steve's advice...he is a straight shooter)

You also might consider the rumor (probably more than a rumor), of a new Korg PA-900, which will be probably more advanced in some areas than the old TOTL PA3X and, of course, the more mediocre PA-600, and would likely have addressed any small issues found with those instruments.

Plus, with the PA-900, you will have the advantage of built in speakers, which will be ever so handy for quick rehearsals (I miss having an S910 for that reason alone), and you seemed to really like the old PA-800 (the one you are hugging in your forum pic) that it will, no doubt, be based on.

Maybe a reasonably cheap second hand PA-800 (or even a PA-600-but that doesn't have a vocal harmony) to tide you over till the PA-900 is released, and to also let you get wet without diving straight into the playing pool, not knowing yet how deep the water is, if you get my drift?

Good luck with whatever you choose, and best wishes in regards to getting back into playing, at whatever level you decide on.

Ian