Great post Les. Makes me think... while the Kemper is known to capture the amp "as set," the other modelers claim more to mimic the amp at any setting... but it seems to me that many models sound a lot like the real thing at "some" settings, but then don't react to changes the way the real amp does. Few clean up well with guitar volume knob, for example. Few high gain amp models sound like the real amp with the gain down... Seems to me that even modelers that claim to mimic the amp have a sweet spot or at least a smaller range of sweet spot where they may come really close, but others where they aren't close.
I think the Axe guy one time said that if you literally turned the dials from 1 to 10 one at a time, and accurately reproduced all of that range in every control, models would have such huge file sizes that a modeler could only hold a few amps. Seems like they try to get what they consider the sweet spots as close as possible and from there you often get further from the real amp the more you turn the knobs.
There was an interesting conversation going on at TGP a while back, comparing the Mark IV models in several modelers. One guy was swearing one was way better, another claimed another one was say better... guys agreed on both sides... the end was when it got interesting. Turns out one guy was playing fatter smoother, (Santana type tones) and one guy was playing metal. When the guys went for the other guys tone, they agreed with the other guys opinion. In other words, one modeler did a much better heavy version of the Mark IV, while the other did a much better fat smooth signing gain type tone. Seems that's the way the designer wanted "his" Mark IV to sound so that was the best tone in the box for that model. That's the one he used to create the model, or whatever.