Well, I'm not sure everybody here is ready for that sort of a tirade

.
But here goes nothing.
While discussing the vibe of tube amps in my first post, I was definitely considering "lead" guitar pretty exclusively. That's where the musicality of the amp itself is most revealed in my opinion. That's where the subtle issues of tone and articulation really rear their ugly head. That's where tube amps get really sexy. In my opinion it's a whole different can of worms when you're talking about heavy rhythm guitar. Some of the same things are true, but alot of different things come into play as well.
With the proliferation of lower cost solid state amps, digital amps and modelers in recent years, as well as a trend for over-processed unrealistic tones, people have become acustomed to a whole different kind of heavy guitar tone. I deal with people all the time who have totally unrealistic expectations of what an amp should sound like. I also deal with people who try out a tube amp for heavy rhythm and are disgusted by it. A modeler or a solid state amp with an abundance of shrill, grating gain is what they expect to hear.
When it comes to heavy guitar sounds, you have a declining number of listeners who "get it" combined with a growing number of guitarists who "don't get it" so you almost end up creating a new trend or a new definition of a good guitar sound. The thing is, alot of those same people are able to acknowledge when somebody reeally kicks their ass with a guitar sound, but if you told them what it took to get there they would cringe and run away. You ever heard a live band where the guitar was just roaring at you with these huge teeth and this brutish howl? That guy gets it. The guy who doesn't get it hits a pretty sweet sounding chord before the band starts playing, and after the song starts you can't hear his sorry ass anymore.
Give me a modeler that will recreate the chunk, the clarity and the girth of a "money" tube amp with the gain rolled to about 12 o clock. It's not happening. When you dime the gain on a tube amp, sure, you get saturation if it's a high gain head..but the saturation is not the fundamental element of the sound. You get the sound when the gain is up high enough to make those chords growl but not enough to flatten them out. That is a quality exclusive to tube amps in my opinion. You can argue about it till you're blue in the face but it won't change my mind. You won't change the mind of just about any tube amp user so if you want to argue about it you should get your head out of your ass and try and pick up on the trend there.
Pushing a quality amp into the danger zone is like taking something that you know works and trying to coax even more out of it. You've got something to build from. You've got to get a handle on what elements of the sound make it good, or make it big. When you go to the fringes trying to get an unholy amount of gain you've got to keep sight of the part that sounded so good. I can dial my amp into that sweet spot with no problem. Trying to dial my VOX or V-Amp into that territory is a waste of time. You sweep it through the gain range and you never hear that fat growl in any form. It's just not there. Sure, when you crank the gain you end up with some of those similar saturation characteristics at the top of the range, but you blew right past the part where you had any balls in the sound to begin with. People who think that the modeler cuts the mustard for heavy guitar sounds gotta be blowing right past that part of the sound too. Or else they are just another one of those people who have redefined what sounds good in a guitar sound in their own opinion. There's nothing wrong with that. I got no problem with people who love their modelers, god knows I use mine when I need to. But the magic of a tube amp is definitely real. If you can't pick up on it you just missed the boat or something.
Of course you've got plenty of people who disagree with me on what elements of a guitar sound make it awesome. People disagree on what makes a guitar sound big. Perhaps it's too bad for me that I have to be one of those people who cannot be satisfied with less than a bitchin tube amp, I wish I could get by cheaper.
Oh well...that's enough for now.