Musical Fidelity and Sonus Grand Piano too bright.

Thanks for the thoughtful and experienced response, Jimmy. It's the electronics - if you've heard them you'd know that that series of MF are quite bright and take careful matching with speakers.

IMO cables and room treatments should be used as a final tweak for a system and not a remedy for characteristics of the components themselves. If not, get ready to spend a LOT of money on silly gadgets and snake oil in your quest.

GHunter - there's more to it than what you say. The point not to adjust your room to the equipment (and forget about cables - I never mentioned them) I agree with and am not advocating.
Most importantly, my point is that if you have a crappy room, going around trying to solve its problems (especially in the highs) by replacing numerous pieces of expensive equipment is not the right answer either.
Lastly, taming highs with things like damping, whether curtains or relatively inexpensive retail products, is not snake oil and is backed by simple science.

My point is simply that you have no experience with the equipment in question and are too quick to suggest an overly simple solution to a well-known issue.

I thought it was common knowledge that damping at the first and second reflection points was (nearly) mandatory, unless one has a rather large room. I doubt that that has changed, regardless of equipment. HP, whose room I have been in, has damping at the first and second reflection points ALL the time -- and this is in his main room, with the AGR speakers.
Electronics simply sound brightER in a non-damped room; they WILL sound bright, period, if they ARE bright,unless the partnering electronics have a droop in the treble.
I've used Tube Traps since 1986, as well as RPG reflectors, and I can't imagine any room less than 15' wide not needing reflection at the first (and second!) reflection points. To NOT be doing this is throwing money away: one is simply hearing the room, not the equipment at its best

Ghunter - 99% chance of room problems, the MF piece is fine. Room acoustics are WAY more real than audiophile amp-inherent brightness.