john,

I still have the Pa50. It's still good enough and the sounds, if not up to date, does not make you ashamed.

I don't think Pa500 is such a great step forward (is is, but not a huge one) so I'll be waiting paciently for the next line of "cheap" arrangers from Korg. In the meanwhile, Pa50 serves good as tone generator, arranger and controller. Good enough for me, for now.