Hi. I have a pa500 and a Psr1500 (the previous model to the s700). 90% of Korg sounds are very good. Only sweet, cool, live and Mega sounds are worth in Yamaha, Xg sounds are very bad. If you want a very good controller take the Pa500 (not good key feel though). If you want plenty of styles take the Yamaha.
Korg Pa3x 61 - Mediastation X76 - Yamaha Psr s900 - Korg Tr61 - Roland PK5A - NanoKontrol - Ensoniq SQ1 - Yamaha D85 organ