Power for Sonus Faber Grand Piano Domus

I have a pair of these powered by a Unison Research Unico Secondo - rated at 180w into 4ohm.

Forum posts say these speakers need lots of power and wonder what set up others may have to get the most out of them.

My mids and highs seem to be spacial and well detailed but the bass seems a bit blubbery, not as tight and sharp as i like.