3B SST or 4B SST for N804s?

Any help appreciated...I have a pair of B&W 804 Nautilus speakers and am in the process of selecting an amp. I like the Bryston sound and have auditioned the 4B ST, but have not heard the 804s on the 3B SST. The cost saving between the two ($600) is significant to me...will I miss very much if I go with the 3B SST?

Thanks in advance for any advice!
Jadeeye