I think you have an amazing set of speakers in the Vienna Acoustics Beethoven's. It would be unfair to comment on the Revels since I have never heard them before.
I can say that I have spend numerous hours in front of the Beethoven's doing critical listening with my own CD's and found them to be exceptional speakers. Midrange was extremely impressive on these and the bass was more powerful than you would expect from a speaker of it's size.
The source equipment used was a VTL ST-85 tube amplifier and the preamp was SS. I cannot recall the brand of preamp, but the CD player was a Naim.
My listening took place in a room about 14 x 18 and it was fairly well damped. Speakers were about 2 to 3 feet from the back walls and about 7 to 8 feet apart.
I thought the combination of the VTL and beethovens was excellent. It could drive these to surprising levels. The only change I would make is to remove some of the damping materials in the room. I thought the high frequencies were getting absorbed. However, this will most likely not be the problem with your average home listening room.
The beethoven is a 4ohn speaker so I can only imagine that is has a fairly flat impedance curve that does not dip below 4 ohms to be driven with such authority.
I disagree that you need more power. The relationship between power and output levels is logarithmic. It takes double the power to get a 3db increase in volume levels. To the human ear, anything under 3db will go unnoticed. So if you have a 100 watt amp and go to 200, you may get 3db. If you go to 400 you may get another 3db. The reason I say this is that often measurements are skewed in spec sheets and don't reflect real world performance. Also, room size and damping items such as furniture, will absorb some of the sound. Don't waste your money and your electricity bill on a super powerful amp; Unless you live in a cold climate and need additional heat to heat the room up so that it's cozy warm. Remember also that just because you have all this additional power does not mean you are using it. Your amp has capacitors, rather large ones if its SS, and they store power for just that reason.
So what would be the point in having all that power in storage if you had such a big amp? Its because transistors are not very linear. They require huge amounts of storage reserve and negative feedback to make them behave linear. A tube amplifier, provided it is properly designed, is much more linear to begin with. It does not require negative feedback to correct for such problems. Excessive negative feedback robs you of some of your dynamics.
I would recommend that you explore tubes. This is such a musical speaker and I think what you are experiencing will be resolved with Tubes. Try and go with a model that uses little or perferably zero negative feedback. You may also need to replace your preamp as I understand not all tube amplifiers mate well with SS preamps. Most do but you should make sure just to be on the safe side. Its all about synergy.
Just my belief and I am sure someone else will disagree with me on that.