Does anyone have a Bryston 4b-st driving horns?

A short answer : NO. I don't think anyone has ever accused Bryston of being warm and tube like. Their virtues lie in another direction, driving inefficient speakers loudly. They are though to be somewhat bright sounding by many. If you have horns and want a warm and tube like sound GET TUBES. Horns are their ideal partner. In SS get something like Pass Labs class A amps. But if your horns are highly efficient , and I don't know any that are not, get a low powered amp , either tube or transistor.

You should at least go to the SST version. Which is where Bryston starts to sound like an 'audiophile product'.

Buy a tube amp. They are simple to maintain. Changing tubes is like pulling a carrot out of the ground. To add a tube simply line up the notches and push down and sway very gently and the tubes slide into place.

Try this and you will not look back.

Yeah, and the guy who was just unhappy his tubes suck, and to buy a set of new power tubes is gonna be $800..
Sure, go tubes and don't look back. Until you blow your first powertube.
Just bringing up the #1 reason NOT to actually buy a tube amp.