Wilson or Kharma

Let me start by saying that I know this is a very subjective question, still I need some valid opinions. I am thinking about going a different route with my system (I am currently using Martin Logan Prodigy's powered by an ARC VT-200). My room is 19x15x11.

I have a couple of reasons for the change:
1.I would like a speaker that did not require as much power, and I could in essence have more amp. options in this regard (although I do want to stick w/tubes).
2. I would like a speaker with a little more low frequency "impact" than my ML's (this might take the Kharma's out of the running??).
3. The Prodigy's are quite large, something a little smaller might be the ticket.

I have never heard either the Wilson W/P (7's)or the Kharma's (3.2's) and am going on review's and Agone feedback and threads. I would of course try to audition before purchase but it might be hard as there are no dealers for either of these brands in my area. I would like to buy used so that might be a concern as well.
Any feedback on this would be great........... anything else I should really consider???

Thanks
cmo