Now THAT would be smart, but I don't usually do the smart thing. Seriously, thank you for the suggestion. I mainly want the 4B3 for a second bedroom system and am pretty sure the 28B3 will go in a finished basement/playroom area much bigger than the bedroom. It's mainly an excuse to get "both" or should I say all 3

.
In full disclosure, I had 28BSST2's and loved them. Yes, I was an idiot to sell but when the upgrade bug bites, I fall pretty hard. I've had a few detours along the way but am back on track now, heading back to Bryston. I plan on using a tube preamp to start with on the 4B3 and then figure out what to use with the 28B3 should I end up them.
Another friend is absolutely loving a 4B3 that he's testing out. Now he's thinking about either 7B3's or most likely 28B3's.
Looks like the new Cubed amps are amazing.
How about holding off, and listening to your friend's 28B3 first?
Then make a buying decision -- 4B3 vs. 28B3.
cheers