A little update. I purchased a pair of Elrog 300B's and I briefly put them into the BeePre today. With very little listening time I was impressed by the sound, so much so that if I can sell off some extra gear, I may consider buying a second pair for the BeePre (this pair is for the Paramounts).
Compared to the Russian tubes in their now, the Elrog's are significantly more microphonic. The Russians I can beat on the top plate and have very little ring. The Elrog's on the other hand ring like a bell. I might add, it's a beautiful sounding bell but they ring none the less. I find they are a little noisy too in the Paramount but I couldn't get a feel for the amount of noise increase their would be with them in BeePre and the EML's in the Paramounts. It's a very small increase but an increase none the less.
BTW, the red rings sit on the tubes just fine for about 2 seconds. Once they heat up a little they become slick and they slide off the side of the tubes.