I saw this band in Japan last month using a xiosynth :
http://www7.ocn.ne.jp/%7Etolsilo/con...esiloeigo.html
she'd customized hers with strap pegs so it was a keytar. very good sound for such a cheap little keyboard. she ran hers though a distortion pedal, thats it, and i think pretty much used one sound the whole set. I would say that the power in these synths are finding a cool sound and using it, battery operated too. it's not really good tweaking all the time so i'd go for the smaller more portable one with less faders.