Although I am one of those that expressed a personal preference for 45s and 2a3s over 300bs (I own a pushpull 45 amp and a parallel SET 2a3 amp), I hardly think it is fair to say someone is wrong or inexperienced for have a contrary preference. A friend of mine who owns more than a dozen different amps, many he built or modified, prefers a 300b SET amp for his setup. His custom horn system is 105 db/w efficient and his room is not very large, and he listens at fairly low volume, so power is NOT an issue. In this case it is more of an issue of system matching. The horn loaded bass driver does not go low enough for the punchier, better controlled deep bass of 45s and 2a3s to matter as much, and the slight leanness of his system's upper bass/lower midrange is nicely compensated for by the upper bass bump of the 300b. This is a case of different horses for different courses so no there is no absolute superiority of one over the other.
Martykl, I've heard AN/Es being powered by pushpull 45 amps in a very large room and was actually surprised by the volume that speaker can deliver, given its somewhat modest efficiency. I don't know how it would have sounded with a 45 SET amp however (SET would be roughly half the power). I prefer that speaker a little bit away from the corner because its bass response can be a bit too much in the corner. Because Audionote speakers have a fairly warm warm upper bass and lower midrange response, I would have some concerns with 300bs overemphasizing these qualities. Still, one never knows without a trial.
One more thing to add. There are certain 300b tubes that are better at controlling bass and reducing their loose and overripe upper bass response. I am talking about the Kron 300b. It is no longer made, though new stock is still available. Because of the close relationship between Kron and Emission Labs (EML), it would be worthwhile looking into EML's current production 300b (I use their fantastic 2a3 tubes myself).
