I went through the same problem. XP-30 or RS-9. I weighed all my factors and purchased the RS-9. Here are some of the factors: the first big 2 factors in my decision making were 1) I own a JV1010 so I have nearly all the XP-30 sounds. I don't care for the Techno board and I can upgrade my JV1010 with the Orchestral board. 2) I really needed at least 76 keys.

To try to answer lprisan:
The keyboard on the RS-9 is to me as good as the XP-30's. Both are much better than the XP-50's which I traded in. I used the attack and release knobs while the RS-9 was conntected to my JV1010 and the knobs sent the info to the JV1010 thus the attack and release were effected on the JV1010.

I'm impressed with the midi control of my jv1010 with the rs-9. The "dual" button also layers the jv1010. I had the RS-9 in single mode connected to my jv1010. I had both synths set to a piano sound. So I had a nice layered piano, then I had part 16 on the JV1010 set to a strings patch and part 16 of the rs-9 set to a harp&strings patch.

The song I played really comes alive in the 2nd verse. So I played the first verse and chorus in single mode (piano only), then hit that "dual" button for the 2nd verse and the song jumped out. It was very nice. I think the rs-9 is really cool especially with a jv1010 attached.

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RW