I came across this article some time ago and really enjoyed looking
reading.
Tube be or not tube be…
Perhaps just tooobey
Are you a tube sorta guy?
Definitely in the “Tube B” camp: 8 tube system: BHK300’s 2, 6922’s each, Audio Research LS28 4, 6H30P tubes. Like what I hear.
Ha! I have 8 tubes in just my pre…

I"ll see your 8 and raise you …never mind. You win. I’m too happy with the sound of my system, so I"ll stand pat.
Good high level summary without having to read a book, many thanks 
Glad Ultra linear got a mention!
Glad you enjoyed it as well, you are right about degree of quality information
in one place.