Great points all around! Practicality should be a major contributor to one's decision-making when it comes to choosing between options, IMO. I know James has said this more than once...and for good reason. Bryston's amps, I've read, don't differ so much in flavor, but rather in getting more as you move up the food chain. Certainly 28's would add a lot to all systems, but that's not to say that the 4B cannot get you where you need to be.
A little update, last night I popped in my copy of Dave Matthews and Tim Reynolds Live at Radio City....first, let me say that that disc is fantastic - highly recommended. Back to the 4B, I noticed improved staging and richness since first implementing the 4B into my system. Not to be cliche, but I am more and more impressed each time I listen to it. Both the guitars and vocals seemed to float in my room rather than sound like it was being projected from speakers. It was only when the crowd applauded that I could place the speakers' locations. It was really neat.
I hope more positive changes ensue as the amp along with my other new peripherals break in further. More to come....