We'll, I can give a pretty good review. After my stock Ruby's went, I put a set of JJ EL34L's in. With daily use, and weekend gigs, I got a full year out of them. It's now time replace them. They never red-plated or blew, it's just that after a year, they have no clarity left. Flubby and fuzzy. But I've never really gotten more than a year out of any EL34 of any brand. Compared to the Ruby's, I found them more round, with more bottom end. The Ruby's always seemed a little stiff to me, especially at high volume. The JJ's were more natural, fat, and punchy. They were easier to play at high volumes, as they were more relaxed. I was thinking of trying SED EL34's, but if the master is thinking of going with JJ's, I might just order another set. They are the best priced. I've used JJ KT-88's in a Marshall, and always put JJ 6L6GC's in my Recto. I've never had a reliability problem. You just have to buy them from a good source.
*I heard Bogner started putting the JJ EL34L's in the Ubershalls.