I've done further listening and will answer my own question. The original dealer DID have a pair of Paradigm S2's to a/b with the Revel M22's. Both are excellent. I listened through Rotel gear, including the fancy pre/pro with the lcd on front, and a multi-channel amp with 100/pc or so x 7. Two-channel direct, no sub. Stand mounted, about 12 feet apart with me centered on a couch 15 feet back.
Both have surprising bass extension for their size. I've never heard lesser Paradigm monitors or Revel M20, so maybe I shouldn't be surprised, but I was. I'm guessing they are both fairly strong down into the 50-60 hz range. The M22's sounded slightly deeper, but the S2 offset this with what sounded like a little tighter slam at 60 hz or so. The S2's are front-ported and the M22's are rear-ported. I'm thinking the S2's may have the best of both worlds if they're placed close enough to a wall... they may pick up a little more extension there while keeping the slam. But the M22's do have slam and the difference between the two is not large. And both actually picked up the 32hz organ note in 2001 Space Odyssey. My CDM1NT's have no slam because they drop off dramatically before 60 hz where the bass-line slam seems to be in my material ("Give Me One Reason," perf'd by Junior Wells). Either speaker would be a major upgrade for me based on this improvement alone. (Music used: Telarc recording of Beethoven's Ninth; Telarc recording of Also Sprach Zarathustra(2001 Space Odyssey); Monster Blues, "Give Me One Reason," performed by Junior Wells.)
Midrange. The M22 is very neutral. I detected no coloration at all. The S2 seems to have an ever so slight hint of coloration affecting alto-level female voices down thru Johnny Cash's baritone. However, I really mean "ever so slight." I give a slight edge to M22's midrange. (Music Used: Cyndi Lauper's "At Last"; Norah Jones "Come Away," Elvis Costello duet with Lucinda Williams "Scarlet Tide.")
Treble: M22 has detailed but not bright highs. Off-axis still pretty good. No complaints. S2's sounded just a little brighter, but they are not overly bright, either. M22 has a tweeter adjustment on the back where you can boost or cut highs. I didn't play with this because I detected no problem with the default position.
The M22's seemed the most technically perfect, soundwise. Very neutral and very balanced. I like them better than the larger Revel Performas, which ALL sounded way too bright to my ear. And I could sonically locate the tweeters of the larger Performas from a distance, but not the M22s. Supposedly they all use the same tweeter so the difference must be in the crossover. But a difference there is. This is a very good speaker.
Nevertheless, the Paradigm S2's seemed to image better and seemed to have a little tighter bass within a slightly less-extended range. And they have a more curvy style to them where the M22's are rather boxy. The demo M22's were finished in black ash and the S2's were finished in an attractive, laquer-cherry. I'm a sucker for cherrywood, but this is paradigm's least-expensive finish in this range and it's shallow and dings easily as evinced by dings on both the S2's and S4 (which I also evaluated.)
I had to go to another dealer while my sonic memory was still fresh to listen to a pair of B&W 805S's on similar Rotel gear. There seemed to be a distinct midrange coloration when I listen to Johnny Cash's renditions of "I'm a Drifter," and "The Beast in Me." I'd call this coloration a slight boxiness, not particularly chesty or boomy, but boxy. I found the tweeter to sound detailed but not bright. This speaker has the least bass extension of the three models I tested. It could not reproduce the 32 hz organ note and had no slam, even when assisted by a B&W ASW700 sub. The reason is there seems to be an aggressive downward slope down at around 60-65 hz. There was no way even with variable-crossover sub to fill in the bass-line slam on the Junior Wells song. HOWEVER, these speakers far and away had the best imaging of the three models.
Final assessment:
Revel Performa M22: Most neutral and extended frequency response. But they had the least imaging, although at the end of my session I discovered that if the tweeters are 6-8" ABOVE my ear plane they sounded better. In retrospect, these needed taller stands so my judgment regarding imaging and soundstage is suspect. Least appealing aesthetically. The demo pair was in boring black ash. There is cherrywood available, amongst other options, but Revel's website has some broken links for viewing the cherrywood photos. $2,200 USD.
Paradigm S2: Most dynamic, 2nd best imaging, best slam although not quite as bass-extended as M22. Very balanced but slightly less neutral than M22. Excellent styling imo, but fragile finish. $1,900 USD. Different, heartier finishes +$300.
B&W 805S. Detailed but smooth highs. Some midrange coloration. Least extended bass of the three and little or no mid-bass slam. Very best imaging and soundstage. My favorite, aesthetically, in light cherry, followed by the S2. A very strange animal. If I buy this, I do it for imaging and looks. It's tough to justify the $2,600 for these two advantages alone. Morever, these cannot rock, ever. 90% of the time, that's fine, but come Saturday morning I like to play some Zeppelin, some Rush, etc., and these just aren't right for that, or for big symphonic recordings with deep percussion or organ.
I'm leaning very heavily toward the Paradigms because of their tight bass, they seemed to image better than the M22's (although I found out too late that the M22's needed to be higher--I may need one more listen), their looks, and where the M22's had any advantage it was slight. I may even go for the S4's which add bass-extension and sound better than many full-blown floor-standers. Purists may prefer the M22. It's difficult to find ANY weaknesses in that speaker. But B&W 805S now sounds to my ear like a special purpose speaker, for female vocals and imaging mainly.
