NOS Mullard xf2 vs. Amperex BB xf2-x5

i have EL34 monoblocks that require 8 EL34s per monoblock. I currently have NOS Mullards xf2 double o getters in the monos. They sound amazing! I have been reading about the Amperex BB xf2-xf5 (double d getters) and some claim they are the best NOS EL34s. Has anyone compared the two? what are the sound characterists that distinguish the Mullards vs Apmerex EL34s. Thank you.

Regardless of the answer to your question, I seriously doubt you could find 16 NOS Amperex "double d" EL34's, even considering some may have a different label for the brand. Finding these in a quantity as NOS is ultra rare like metal based EL34's and Mullard XF1's.
Thank you for your reply. I guess I should of clarified that although I would prefer NOS Ameperex double D's i would be willing to settle for ones that test strong and those can be bought on ebay. I just want to know what other Audiogon members think of their sound vs the Mullard xf2 double o getters.
Back in the day I used them both and on the classical music I listen to, much preferred the BB.

But I agree with Tis49, the chances of you getting good ones in the shark tank that is tubes today are slim and none. Which is why I've given up on tube amps.
"Tests strong" means got a few months left in the them sort'a maybe.