I sell 300B amps to folks who need or want them. I would never recommend a 300B when a 45, PX-25, 50, or 2A3 would suffice.
All things being equal, i.e. the speaker can be driven by any amplifier, the 45 kills the 300B all day long.
Anybody with half an ear would know that.
Perhaps even you John.
Your experience?
LOL, when you get to 50 years, we can talk.