NOS GEC KT88 v.s. NOS EL34 Mullards

Just wonder if anyone can describe their differences please. I mean when you had/have them both, side by side, what's the most that makes you choose one above the other. From the general search I read that EL34 are more softy/delicate kind of valves, where KT88 have more punch, dynamics and power.
Personally, I don't know, own NOS GEC KT88 only and never tried any EL34, so, you help are much appreciated.

My amp is PrimaLuna Prologue Two and I use in the pre section full house of NOS Mullards.

I can only respond based on the difference btw new KT88 and EL34's. There was alot more punch wit hte KT88's which led me to switch to the New Sensor Mullard reissues. Much happier got more of a tuby sound. I also dropped some nos mullards in the pre amp section which gave even more warmth.

My feeling on power tubes is the life is so short compared to the pre tubes that NOS is not worth the investment.
Thanks for your replay, going to try some EL34, just out of curiosity. Not sure which one to get, but I am really interested in NOS TESLA's and some Mullards.
About their durability. Not sure if this is true, may be, but for example NOS 6550 Tung Sol black smooth plates are like mummies, even they are dead, mean under minimum value, they still play good. So, concider that KT88 were step forward from 6550, they must last longer or at the same level as 6550 at least, I guess.