Amen to that. It seems that some people (though probably not as many as with some other products) have such a bizarre need to defend the kemper as always being absolutely spot on. It feels.. .religious at times.
I know exactly what you mean. Sorry to @Webb for slightly taking this off topic but after this I'm done lol.
The Kemper, for me playing fly dates and also gigs such as festivals with a quick change over time is untouchable and indispensable for me, it really is one of the greatest if not the greatest tool for me out there without a doubt. A while ago I wouldn't have believed I could get my tone and all effects in a single bass drum pedal gig bag and carry it on a plane as hand luggage, that is really out of this world for me.
I have also experienced so many times my tone to me has been much greater than say the other guitar players tone. That would be me going direct to the FOH with the Kemper compared to his real head, real 4X12 and real mic setup, due to either incompetent engineers, bad rental/house gear or rushed setup and sound check times.
However, I cannot say that the Kemper, even when using my own profiles of my modified Marshall JMP Super Lead (which are as close to my amp as I can ever imagine getting) or any others for that matter sound as good as my real amp at gig level, my real cabs with a good SM57 positioned correctly on a stage with enough space to keep spill to a minimum. The real thing just has that extra cut, moves that little more air, fills in the sound space that bit more, reacts that little better. After all, once you have you gear dialed in exactly how you like and mic'ed exactly how you want no matter what, the profile is an approximation/simulation of the real deal and that's the facts. But if the amp is falling just a little short of what you want to hear, the tweaks you can make in a profile of that amp within the Kemper could actually improve on what you hear from the real amp no doubt.
When I have the time, transport and space to set up my full Marshall stack I actually still run the Kemper with the 4 cable method for just effects in the front of the amp and the loop of the amp as I love the effects in the Kemper bar the lack of a plate reverb. This way if you switch to a rig with the Distortion Loop turned off and turn on the Amp and EQ within the stack section I can still get a sparkling clean sound out of my cranked single channel Marshall.
Having the Kemper means I have the choice for the best of all situation that should arise.