Kurt tank, Though I can't comment on the match with your particular speakers, you match my musical taste +/- 10% and approx room dimensions 26x18x10 with rugs and the same sonic properties. Speakers are also on the long wall. I run the RM-200 with ProAc Response 3's, at realistic sound levels at times also.
Now to try to answer your questions: (with my speakers)
As far as power, For my speakers ~86-88 efficient The RM-200 has no problem driving them at realistic sound levels, (loud).
Soundstaging and Imaging. Well, this is one of the things about this amp,that really turn me on. Soundstaging is well beyond the boundaries of the speakers at times, as much as 90 degrees, and even more with certain DVD music concerts. Depth on certain recordings, seems endless.
And imaging is upfront and personal on female voices.
NOTE: This I only achieved, after I replaced the 6550's with KT88's, after speaking with Roger Mojeski himself, in a phone conversation.
As far as the Bass getting deep and tight enough you ask? Well, it didn't have the Slam my Krell use to have.. BUT it bettered my lower end CJ's and AR's I've had and heard in the past. Yes it goes deep, to the point were you can feel it, and tight, on a scale of 1-10, my ex Krell being a 10, the RM-200 would be a strong 7-8 IMHO.
There are a lot of other things to take into account, namly the front end.. CD player, Preamp, Cables, etc.
My post to you is based on my system, taste, and ears.
So I hope this helps you out to some degree or another, with that said.. I wish you the best of luck in the New Year and hope you come to a Sonic Conclusion soon.
P.S. Let us know how you make out.