SET amps and "efficient" speakers

When considering SET amps with 300B series tubes, what speakers pair well with them. I’m only asking out of curiosity after reading other forums where folks said they required “efficient” speakers beyond 92dB (!?). Horns? What models? What are the pros and cons? I think (dangerous!) it sounds like small venue acoustical, jazz, etc. (And no, I’m not about to give up my BHK 300s and Focal Supra No. 2s.)

Just trying to educate myself, so don’t waste your time unless you feel the need for a little fun.

All my best.