EL 34 vs. KT 88 ---- What's the difference?

How about "more to my liking." Better looking? Easier to dust...repels stains...dishwasher safe...A Good Housekeeping seal of approval...burns your fingers slightly less when touched (actually true with KT77s)...preserves the smell of the original recording space...can be used as money in Easter Europe...dry cleanable...slightly slows down fast parts and speeds up slow parts...quiet when not in use...

Another neck snapping time jump...I have to mention (really...it's a required thing) that after using various tubes (including all the ones mentioned by bob) in 2 recent power amps including a wonderful Jolida 502P, and currently a Dennis Had SEP HO (that's right...a HO...says it right there), I discovered Gold Lion KT77s and they're now my favorites by a wide margin. Highly recommended. This took me a while to discover as I'd bought a pair of JJ KT77s and they're not so good and they put me off 77s altogether, but the GLs are different and sound so much better it's kind of amazing.