Why don't you try to contact Paul McGowan, designer of Genesis B-200 and owner of PS Audio (www.psaudio.com). His new amp, which can be considered a much updated and improved version of B-200, should be ready to ship soon.
From what I've heard there is a physical limit to the amount of air a maggie can move. If you pump in power past that point it will have no effect other than to cause distortion that often creates a rattle. If you need ear-splitting loudness in a large room the amp is probably not the problem, you'll need a different sort of speaker. The Brystons are IMHO fully capable of driving the Maggies to their maximum sound pressure level.
IT is strange that folks think I am pushing past the limit.
With the same set up except useing transparent bi plus. I could open past the 1 a clock mark, in fact I could open up all the way. I do not turn it that high for the most part but could till I put the transparent bi super on the system over the transparent bi plus.
At 1 a clock if I am not in the same room it is not all that loud. Some recordings of world music or jazz at 1 a clock is not that loud.
I think Finburg is mostly right about the rattle.
I think I will have to buy a new set up for the other parts of my house.
Any insight into the transparent plus to super change?