Larry nailed the issue. "All amp sims are still severely lacking"
Nothing out there currently, marginally resembles anything real. They put a brand name on it, get some fading rock star to endorse it, and hope that's enough reality for the masses to fire up the credit card.
We do not have the technology for another 20 years or more to do a real simulation of any live amp hardware. Too complex to deliver.
Amplitube 3's opening page is admittedly clean Fenderish though... As long as you don't have to resort to overdrive when everything falls apart.
S-Gear is cool, and doesn't try to push Orange, Vox, Fender, Slash, Marshall down your throat.
Respect Head Case also for an open, roll your own approach.
John