@jafant I heard the Bryston 4B3 + BP17 Cubed with Vandersteen a few weeks ago at a very high end shop. Being a previous Bryston owner I am familiar with the sound. The top end was definitely less harsh and the sound and soundstage was similar to the Benchmark AHB2 (which I just sold).
The only thing that struck me as a negative was that the sound was not projected out from the speakers as much as with the Mark Levinson 585 integrated that I heard 20 minutes earlier at another shop. I noticed the same thing with the AHB2 when I compered it to the ML 585 and Magico A3 (same room same gear).
I spoke to Gary Dayton of Bryston and he said that the BP 17 is the best sounding preamp in the lineup now and that the BP-26 will get cubed soon.