Fascinating thread chaps.
I have to say I'm a bit biased (no pun intended) here, but I absolutely adore my Kemper.
I would say that where the Kemper really seems to score in the tone-mapping department is that it doesn't try to model a 'complete' amp. Rather it simply sets out to capture and emulate a 'snapshot' of the settings on the amp when it's profiled.
You are advised, when profiling, to set the Kemper's Gain and EQ at approximately the same position as they are on the amp that's being profiled. This is so that when you are playing the saved profile, any change you make in those settings will theoretically mimic the changes in the tone that would happen if you changed the respective dials on the amp.
However, in practice, once you start to drift away from the 'stored' settings, especially the drive, the results, although usable, progressively become less faithful to the tone from the 'real' amp if it were being tweaked correspondingly.
To these ends, most rigs available to download, especially commercial profiles, do not just come with one single 'amp profile'. A specific amp would typically be profiled with a range of settings from each of its channels. Some of the better profilers even supply their bundles with profiles taken using different cabinets and microphone combinations (and even with different positioning of the mic with respect to the loudspeaker).
Obviously the more variables to the combination of amp settings/cab/mic you add, the more profiles you will need to take. On the other hand, if there are just a couple of 'sweet spot' tones from your rig that you tend to use most of the time, then these will be the only profiles you need to make.
In conclusion I'd say, that in my opinion, the 'accuracy' of the snapshot profiles is never compromised by the Kemper trying to be a jack-of-all-trades. It does what it does extremely well, and doesn't pretend to be able to be able to create a faithful emulation of a 'complete' amp.
Some might view this lack of versatility as a weakness in the way the Kemper works, but when you take into account how good the snapshot profiles are, the extra effort to capture a variety of tones is easily justified.