Thanks for posting this! I thought it was an excellent review and I like his simple, no nonsense writing style.
I also want to add that I just picked up a pair of Elrog 300Bs for my Paramounts. There's been a lot of hype about this tube. Also, reliability and availability issues. Supposedly, Elrog has made some changes which has improved reliability.
As for the sound, it's that rare occurrence where the item lives up to the hype! It seems to combine the best attributes of the EML solid plate (clean, transparent) and re-issue WE 300B (warm, smooth).
The Elrog 300B's gain (or is it output power?) sounds a little less than the other 300Bs I have used. Therefore, I have switched back to higher gain WE 396A input/driver tubes for now. Via adapters, I had been using lower gain 6SN7s.
Of course Elrog 300Bs are much more expensive than the tubes evaluated in the linked-to survey but... they are about half the price of re-issue WE 300Bs. I bought my "like new" pair of Elrog 300Bs on Audiogon, so I'm not sure about their current availability. You may want to check with George at Tubes USA.
Gerry