Interesting to read, can you expand a bit Pez.
I've got some KT88 treasures which have been pretty darn good. My experience with Psvanes has been primarily negative though. I hated their 845-T and wasn't wild for their 12au7 or 12ax7. In fact, i turned a couple Psavane 845 owners onto 845B and they never looked back.
Tipped up tonal balance, less body, more resolution, strident, less emotion.