Any Bryston 4B3 amp owners out there?


I'm strongly considering a 4B3 amp purchase. Bryston's warranty and build quality are as good as it gets and the price is in my budget. Pro reviews are good, I'm just wondering what owners may think. Are you pleased with the performance, what it's matched with, etc. I'm already aware of the specs, the story behind the design, and all the press release stuff. Plain talk would be appreciated.

Thanks 
professorsvsu
@professorsvsu,
Congratulations on the decision. Would love to read about your comparison between the A21 and the 4B3.
The second week in February I'll free up some cash and make my move. If the 4B3 doesn't please me, back to the drawing board. I'll certainly share my personal comparison between the A21 and 4B3. If I can just dig out some of the upper mids and highs that the A21 wants to bury and keep it's soundstage and bass, I'll be pleased. 
I own a 4B-ST and 4B-SST2, and both sound quite different.  Sort of a good thing though, as they match better or worse with different speakers.  The ST sounds more exciting, and maybe less refined.  It's lived most its life powering my B&W 801s2's, and is a great match for them.  The SST2 is too refined, and almost sounds compressed powering the 801's.  I've just had the 20yr old 4BST repaired & recapped by Bryston, and it was really worth it! (~$700)
The SST2 drives my pair of Tannoy 15's, and the low noise pays off there.  The ST is too harsh on the Tannoys.  It's all about system matching!  I borrowed a Parasound A23, and found it too bright.  I've not heard the A21 in my home.   I am SST3 curious, but not in the amp market now that my ST is restored! 

My A21 has a lot going for it, it's just not enough. Too many times it misses the mark and has limited my music listening choices. I also own the Parasound JC 2 BP preamp, and for better or worse, almost certainly will hang on to that. The amp will be the final piece, with Bryston, Simaudio, Mcintosh, and Pass Labs all in the running. Bryston will be the first and hopefully a keeper.