I personally think the XP-30 is a good deal, because you get some sound boards already installed and have the ability to add more
. That is, if you don't mind the keyboard.
I don't own one, I have the JV-2080, but it seems to be a very cost effective way to get the JV/XP sound sources. For me, the main reason for purchasing the JV-2080 was for the larger LCD display. I thought it would be difficult to program sounds with a small LCD display. I used to program alot of sounds on my keyboards, but have since almost abandoned it, due to the fact that there are so many sounds available in these new synths, that you don't really have to anymore.