(1) Yes, they will fill your space with no problem.
(2) I know someone in Denmark who drove them with Butler Audio Monads (hybrid, ~110W/Ch in 8 Ohms) and loved 'em. They were his favorite amp with the Revs for quite a while, but I think he's moved on to a Spectron Musician III Signature Edition.
A common misconception is that SP Tech speakers don't work and play well with tubes. That's not the case at all. In fact, I've spent more time with tube-based amps in my system (Timepiece 2.1s) than SS.
However, what *is* true is they respond very positively to more and better power, but then that's true for most speakers. The the more you have, the more dynamics (particularly visceral) you'll realize.
That's not to say tube amps can't produce startling dynamics; they can. But as with all things, there are always trade-offs, and no two amps of *any* type are created equal.
(3) As is the case with any properly designed, very revealing speaker, SP Tech speakers must be fed well. That said, the midrange and HF are as natural and organic as any I've personally heard.
To my ears, IMHO, and all other standard caveats apply.
(4) Again, all standard caveats apply.
I've heard all but *maybe* the Coincident Total Reference (might've at RMAF, but I don't recall). To my ears, the Revelations are better than all of them.
As for other caveats, I own SP Technology speakers (2 pair) and have been a customer for almost 5 years. However, I am in no other way associated with SP Tech, period. I receive nothing in return for recommending SP Tech, nor do I receive a commission should someone decide to make a purchase based upon my recommendation.
Top to bottom, all things considered, the Revelations are the best speakers I've ever heard, and that is my one and only motivation for making this post.
Regards,