Hi Robertofabri,
I am also a lover of Sonus Faber, and I currently have a couple of Olympica II, they sound very good. As an amplifier I use an Audio Analogue Puccini Anniversary that drives them without problems. Regarding your thought of changing your Sonus Faber Exstrema and in relation to your excellent system, you should, as others have already told you, go up a lot to have a real improvement, you should turn to the Sonus Faber Guarneri (stand) or the Sonus Faber Serafino (but here we are on high prices). In your place I would be like this since you are already at a very high level.
Kind Regards
Alessandro Catalano
Roma/Italy