Have run the Bryston 4B on everything from NS10s to Urei 813 (bridged into mono @8 ohms) and it is a really great sounding amp.
A good friend who is not a fan of the NS-10 remarks about mine with... "Your NS-10s sound really good!".
This is definitely due in part to the Bryston's magic.
Also spent a couple of years with a few Perreaux 1000, and I can attest to this amps pleasing carachter.
Both of these amps are MOSFET powered which does add some harmonics that the human ear seems to really like as a pinch of seasoning in the musical Gumbo.