Have not tried the EML yet, but I agree that the WE 274b really pushed it up a notch. Anyone try the Sylvania 274b yet? I have one, but have not popped it in yet. The U52 from Brimar is not as good as the WE 274b in the amp.
I have 101D tennis balls and 101d ST shapes. I prefer the tennis balls, but it is a marginal difference. That said, I am waiting for the OK to let people know about the other tube I have tried that was better than the 101d to me. That said, it is another WE tube.