i use a 211 amp with the 4367 from jbl. i have previously used Audio Note AN-E HE Spe, JBL 4344, Altec 604g, JBL 4349.
I listen to rock and pop. Not jazz or orchestral music most of the time.
with 4367 I don't find any "horn" nastiness. Zero. To me thats the benefit of the tube amp.
Bass is exceptional.
On decent footers, and set 0.7 m from back wall, I find the JBL 4367 delivers extraordinary presence and disappear totally. Feels like sound is conjured in space magically. Very resolving. Very dynamic.
I had a Gryphon Diablo to compare with 211 SET amp for bass performance. Both in room response testing and ears didn't highlight any issues with bass from tube amp relative to 300W brute force of Diablo. 4367s imo aren't well suited to solid state. It can hurt the ears just slightly. The way i see it the 4367 is the modern Altec Madrid etc with all the honkiness fixed. I feel they are overlooked for some reason not necessarily to do with performance. They do take a long time to run in and they don't sound great during the run in period is my experience.