Coincident Frankenstein mk.2 amps

Hey folks, I am coming to this game late (better late than never!), but I have recently joined the ranks of you Frankenstein mkII owners.  I am running them with my Omega Super Alnico HO monitors, which are rated at 97 db, playing in a rather large room (25' wide x open in back, x vaulted ceiling that peaks around 12').  At 8wpc, wow, they sure play loud enough, and I like peaks in the low 90 db range!

Anyways, lots of good info contained here.  I am looking for any updates / recommendations on the rectifier tubes that are being used with these amps, with either the EML 300bXLS and Shuguang Black Treasure 300bs, which I have.  I like the RCA black plate 6EM7 over the GE gray plate 6EM7s that came with the amp. I have tried the Mullard GZ37 with the EML, but that seemed like a bit too much, and too edgy for me.  Now using Sylvania black plate 5U4GBs, and the sound is smoother.  

What others work "best" with the EML or BT?

@charles1dad , I absolutely agree with you Charles, on all counts. Thx!

Mark

Thanks for the feedback on the Mullard GZ37 guys... maybe I need to be patient with them, since the EMLs and the Mullards are relatively new with few hours on them, they have to "burn-in" properly.  Any thoughts on how many hours it may take them to reach their full sonic glory?

@snopro , I am a huge fan of the Jupiter caps, and have already used them in at least 4 or 5 of my previously / current owned gear. Trust me, it's on my mind now for the Franks! I want to get used to the Franks for now before putting in the caps, but yes, that is a goal!