Must congratulate all on an interesting and informative blog.
I looked hard at the R900 and auditioned them twice. Some immense strengths. The depth and stability of the soundstage was really second to none. Good, tight slam in the bass. Vocals also very good. The only criticism that I could make was that on orchestral works, massed strings and the like, and other lounder, complex passages, it all sounded just a touch smeared and there was an "almost but not quite right" quality about it all.
Having read this blog, I decided to audition the 201/2. Comments - after an hour of listening, clearly better than the R900 in several respects. Voice even better and more realistic, amazingly close to "you are there." Overall clarity and seamlessness of the sound, again, better. No smearing and every instrument in my test complex passages stayed more clearly delineated. Little sound cues were present that I just did not notice as clearly with the R900's. Although there was not as much lower bass, it did not seem to matter; there seemed to me to be more than enough. Closer to live, certainly, at times astoishingly so. I still might give the R900 the nod in soundstage depth, although that may have been caused by speaker placement. Will need to play with that.
I do have a big SS amp, a Classe CA301, so driving the 201/2's will not pose a problem. I did at first audition them with a lower-powered amp and concur that driving power is important if the 201/2's are on your list. In the end, they ended up on mine and am looking forward to collecting them shortly.