newscane, one good-sounding recording might be made in almost any way imaginable. But what is the likelihood of getting good sound the same way the next time, and the time after that? One recording can never answer that question. Only continued use in a number of different recording situations can answer that question.
Most affordable tube-based equipment nowadays uses the tubes as distorting devices, in line with the experiences and tastes which a rock-and-roll guitarist might have with tube amplifiers versus solid-state amplifiers when they're overdriven. The effect depends on the gain settings and on how loud the sound is when it reaches your microphones, on its frequency content (its "spectral balance"), on how much distortion there already is, and the acoustics of the room. Yes, of course the result might be really great on one recording--if so, then what a relief: the levels and settings were good for that one recording. It's fortunate that the drummer or the singer didn't play or sing 3 or 4 dB louder than expected, and that the walls of the room absorbed and reflected the sound in the way that they did.
But what if it's different the next time? If you anticipate it, you're golden; if you don't, you'll be disappointed; if you anticipate it but then the thing you anticipated doesn't happen in the way you anticipated it, you won't get the color you want. I'm just saying: it's better if you choose an approach that doesn't commit you in advance to what exactly the performers are going to do that night--since if they're human and you're not God, you never know.
That gamble is part of the excitement, I know, but I'm sure that it also results in many recordings that people don't post on line. To get a realistic view of a recording technique or a set of equipment, you need to hear what it does when used inappropriately, and to find out what recording situations are "exactly wrong" for it so that you can choose something different--or maybe choose knowingly to go with what's "exactly wrong," and enjoy beating the odds if you happen to win.
My sense is that people will be particularly inclined to put a recording up on line in this last case, precisely because that gamble doesn't usually pay off well. Do people ever post their "blooper reel" recordings--the ones that make you groan with regret at having made them so badly? Aren't there Web sites in which people can post anonymous confessions of bad things they've done and said? Something like that, for recordings ruined by our own stupid mistakes, might be very good for the soul and instructive to others.
--best regards