[rob80b]

The majority appear to up-size but back at the beginning of May for various reasons I downsized from a 4BSST to a 3BSST sq , my listening room is only 10 x 15 but I’ve always appreciated the reserve on the 4BSST (I listen relatively loud when I can  ) and was expecting a hit in performance as the previous upgrade from a 3BST to the 4BSST was not subtle and definitely in favor of the bigger brother.
So I’m not too sure what happened this way round, if it’s the Squared updates, which are minor on the smaller amps or whatever but I’m really enjoying the overall musical performance of the smaller 3BSSTsq over its bigger sibling, my Dynaudio Special 25s have never sounded so natural, effortless and correct in timbre, and so where I found the 4BSST a big step up from the ST especially in the highs, likewise now for the 3BSSTsq.
And of course now there are the cubeds….

[JLM]

Every amp has it's 'sweet spot' where the power output provides the lowest distortion levels.  For solid state it's normally fairly high, for tubes it's normally very low. 

If you investigate your room size, listening distance, and speaker efficiency you'll probably find you listen to around 1 watt/channel.

[rob80b]

As you say it's all about the sweet spot and this gentleman here explains it relatively clearly in laymen terms.
"As power output goes down, fidelity may go up, but dynamics will go down."
https://parttimeaudiophile.com/2012/04/03/speaker-sensitivity-dynamic-range-and-amplifier-output/

As it stands now in my room (overly damped) with my equipment and listening habits (louder than average), the 3BSSTsq at a nominal 150 watts driving my Dynaudio Special 25s with a sensitivity of 88dB at 4 ohms, appears to be the best compromise between power, fidelity and dynamics....although Bryston do advertise from the 1st to last watt for all their current amps ....

[techguy0192]

With Bryston there is no good, better, best product.     It's a question of how much power.  I'm using a 3B SST2 in a dedicated 12x14 room.  It has been more than enough power for every speaker I have used it with.  I have also used a 2B-LP that showed no signs of running out of steam.  My next upgrade will be moving to a 2.5B Cubed; very little power difference in comparison to my 3B SST2.

SST² (Squared) Amplifier Philosophy
FIRST TO LAST WATT PHILOSOPHY:
A  significant  part  of  the  design  criteria  for  the  new  SST²  (squared)  was  to  develop 
amplifiers that would maintain an ideal power curve through the 'first and last watt'. Most
amplifiers  exhibit  a  power  curve  whereby  the  best  noise  floor,  drive  capability  and 
distortion   are   maintained   from   about   1/3   power   and   up.   The   new   Bryston   SST²   
(squared) series maintain their ideal power curve right from the first watt to the last watt.
Think  of  it  like  a  torque  curve  in  a  car.  The  sweet  spot  or  the  torque  curve  has  been 
expanded.

[schmidtmike76]

Can't say enough good things about my 2.5 cubed. 

[servingko]

I too, down sized to a 3BSST2 coming from a 4B SST2 with a pair of Middle T's and couldn't be happier.  I am in a smaller dedicated room that is 13.5' X 17'.  I am intrigued by the cubed series and would like to take a listen, but sadly I have no dealers with amps in stock and if I have to order they really haven't added any value and I feel no allegiance to them.

My primary reason to go with the 3 was to fit into an equipment cabinet my son made for me from a converted antique dresser.  For me the 3B SST2 has been great and I have picked up an additional two, along with a TC1 Mini and a pair of TOW's, for a multi channel system once I sort out some wiring and select a projector for the HT room.  I had hoped 4K DLP would be available by now without having to spend more than $5-10k.  Over the years I could have funded an undergraduate degree from a decent school with what I have lost on bleeding edge projectors and I am not doing that anymore.