I was in the same situation that you are in right now a few months ago, but I decided on the RC.
I love the sound of the twin and I think it looks better than the 954, although the 954 doesn't look bad by any means.
Not to mention, as far as I know, there's been only a couple RC's sold here in Charleston this last year. Not bad considering I've seen the blk/silver 954 more than a few times already.
On a strictly performance level, the 954 has more bhp, better acceleration, etc., not to mention it's quite a bit more comfortable than the RC. The RC doesn't come with a passenger seat which the 954 has, but that's fine with me cause I'd make my girlfriend ride the bus before I let her on the back of it anyway.
All in all it's a matter of preference, but the RC is a pretty rare bike down here in the Southeast and I got mine for a damn good price.
Did I mention that it sounds mean as hell?