I think the Sonus Faber's at your house exhibited a bit more of a metallic edge than I'm used to from SF's, though I've never heard the Grand Piano except for at your place. I've heard SF almost exclusively with tubes and they sounded more like what I expected them to sound like (lush, full bodied, great tonal color) based upon reviews I had read of Sonus Faber's. IMO, if I were to switch something in your system to match the speakers better, it would be to change the pre/processor to a good tube preamp. Some speakers just take better to tubes and from what I've heard of SF (Concerto, Guarneri), they seem to like tubes. My Reference 3a's can sound good with SS (Plinius would be a good example), but really show their stuff IMO with tube amplification. In fact, I wouldn't buy the MM De Capo I's if I had SS. You aren't hearing them at their best IMO. For Jazz and Vocals, I think the Sonus Faber's i've heard are a very good speaker brand. If you listen to rock n roll almost exclusively, then I'd probably suggest something else.
Michael