Charles,
Have you tried/heard the Elrogs yet? I am anxious to learn your assessment, as I've valued your input re 300B's.
I have a pair of the Takatsuki's (which are just sublime!) and also a pair of SERP's. The SERP's are very good, but for my tastes the Tak's are worth the difference I price!
I have a pair of EML 300BXLS 'stuck' at US Customs in Chicago (it's been over a week now!), so soon (hopefully 😄) I'll be able to compare those as well.
My Manley Neo Classic 300B pre/headphone amp of course uses a pair, and the AN Quest Silvers I have on the way will also run a pair, so I'm seriously considering adding a pair of the Elrog's to my inventory.
Best,
Randy