Well there is no correct answer to a question like this, just too many variables in play. I would prefer an excellently implemented el34 amp over a run of the mill built 300b. All I can offer is this, if both are designed and executed to a high level I`d choose the 300b SET without hesitation.Of all the different topologies I`ve heard over the years, OTL,SET,PP tube,solid state, class D etc. IMO the SET has provided the most nuanced, musical honesty,realism, true to life emotional experience and presence of them all.The SET was noticeably the least mechanical and electronic sounding{next best in this regard was an OTL] That`s simply my point of view based on actual listening. You and others could certainly reach other conclusions of course.The SET amplifier must have good quality power supply and output transformers and matched with a suitable speaker to appreciate its full potential[generally true for any amplifier].Good luck to you and just trust your own ears, that`s what I did.
Charles,
Charles,