I don’t actively participate on that forum but DubStep Girl’s exhaustive comparison of rectifier tubes was invaluable to me and among the various tubes I’ve rolled, I found her descriptions to be spot on. Of course, market prices have gone up and some of the tubes (WE in particular) are even more unobtanium than ever.
As to using music as grist for evaluating equipment, I think that’s a common thing in audiophile land. It is useful to the extent you are making changes and comparisons, but it can also be a trap that I’ve certainly fallen into over the years.
I can’t claim to be more enlightened- maybe it’s just that I’m old, tired and don’t feel like fiddling around with tube rolling and gear changes at this point- I’m quite happy with the current system and am able to enjoy it as a vehicle for playing music- the obvious goal once we get things "sorted." I know there is this mindset of "never satisfied"-- I’ve been there too, but somehow, I’ve overcome that hurdle at least for now. Maybe it is a question of striking a balance-- between the amount of time spent in analytical mode and the amount of time you can devote to just kicking back and enjoying what you’ve got. Like I said, age, wear and tear, many years tweaking and twerking have gotten me to a point where I’m able to put the audio nervosa to the side and spend the time listening. It may also be the result of having gotten this system to the point where it really sings. I know its strengths and weaknesses and tend to play what I want to listen to, musically, rather than worrying about SQ.