Auditoned a 3BSSt in June; bought a 4B sst in July (it turned out to be one of the first squared); then upgraded to a 3 x7Bs sst SQ in April of this year. Quite the upgrade going to 7B. Both the 4B and 7B were/are run thru a Torus 20 unbalanced (with a single 20 amp breaker). My only regret is not having bought the 7Bs from the outset. If I could afford the 28Bs I would do that. 7Bs have much more bottom end. Total control of the music at all volumes! Balanced tonal if I may say. Cheap Naxos, Decca, and Phillips Classical CDs for example approach the live concert experience! I could go on, but this is my first post.
Hope that helps. Many thanks to all the posters. The input has been invaluable.