You've encouraged me to check out the Rocktron. I love the idea of modelers, but was never quite seduced by one for the reasons I said above. The way you have described this unit- sounds like something I would appreciate.
It's pretty cool.
I have a Line 6 and several Digitechs and the Rocktron smokes 'em.
It's set up more like a multi-channel amp
Instead of amp models per se, they have 4 channels. They're ummmm .... I haven't programmed it in a while ...

...... Clean, Texas ( I suppose a tweed type sound), British and Mega (for high gain) ..... that's it. Makes it pretty easy ...... clean is clean ..... I use Texas for crunch rhythm sounds ..... and British for my long-sustainy type lead sounds. Mega is a bit too hi-gain for anything I do.
Then it has Chorus - Flanger- 'Verb - Delay - Variac --- and some good speaker emulations.
I think it has a couple more FXs than that but I don't really get into it that deeply so I don't remember.
It's for what I said it was for ..... certain gigs where there's just no point in hauling an amp out there and emergencies.
But it really does sound pretty damned good direct. Other guitarists will usually comment on it sounding 'warm'.
And it responds to picking attack better than most modelers I've used though it's not quite up to amp standards. But good enough that I don't spend all night hating on it ya know?
I've dialed in 4 or 5 presets for my Strat and another 4 or 5 for my 'bucker guitars and even another few presets dialed in for using it as a multiFX into an amp although I never use it that way. I even have one set up for bass guitar since I'm a bass player too.
It stays in my truck always .... so in the event I have an emergency, whether an amp breaking down or a sudden gig when I don't have my stuff with me, I always have something I can get satisfactory results out of.
A couple caveats .....the cheapest one, the G100, which I have (it was the first and I bought it when they first came out) doesn't have a tuner and no recall button. So you have to have a separate tuner and you can't just toggle back and forth between two sounds with a single button. You have to select the other sound and then recall it every damned time. All the other models correct this.
I've gotten used to it but if I were buying another one I'd definitely get the G200.
And the display is hard to see if it's bright. Outside it's just freakin' invisible. I have to bend over and get upi close to read it. Inside gigs, it's fine.
IMO, for anyone that hates modelers but feels there are times when you have to use one and don't want to be bummed out by it, the Rocktron's the one to go for.