Sonus Faber Grand Piano Home to Dynaudio S3.4?

An upgrade for sure and a different sound.
Thats my opinion after hearing both.

I seriously looked at buying the SF Grand Pianos, so spent some time listening to them. I then listened to the Dyn. Countour 3.4's. It wasn't a close horse race. The 3.4's ran away from the Grand Pianos. I wound up getting the next up in the line, the 5.4's, and have been happy ever since.
Good luck,
Dan

I've owned the Dynaudio Contour s5.4 and they are great speakers. They will have a bigger sound than the SF Grand Pianos but the SF will be a bit more warm and sweet sounding than the Dyns.