My friend is a bit shy. In response to this topic, he wrote:
"The 4B-ST really makes my F-30's sing. I think that they absolutely need the 4B's power to perform at their best. I am getting full range, nuanced performance from my setup. Of course it helps that I am running excellent front end gear, the ARC LS-3 pre amp & Naim CDX, as well as excellent Kimber Monocle-XL and Transparent Reference interconnects. If I went anywhere, it would be more towards more power and dynamics, probably to monoblocks."
I would only add that his listening room is roughly 13 x 20 x 8, and that my Revel Salons, which are admittedly a different speaker, did like power.