I don’t own a Kemper, but have had access to one for long period of times, sometimes more than one month, and have tested it extensively. I tried thousands of profiles from rig exchange, thousands from commercial profile sellers ; I profiled my own presets, captured Kemper’s cabs, tonematched Kemper profiles, and here’s some observations.
The biggest advantage of the profiler is ease of use. With the right profiles it is a really good sounding plug and play machine. However, I had trouble finding profiles I like as much as my own Axe II presets. I find some for crunch sounds (Marshall and all) or some boutique amps. I didn’t find any for cleans or high gain and had to make my own. So, in my view, unless you have something to profile yourself, you’re dependent on what is available, free or commercial. It’s a big problem for me , specially that tweakability is quite limited – I’m not a fan of the generic tonestack, the EQ is missing LPF/HPF options, there’s not enough options for the delays etc, and swapping the cabs, besides being an approximation (up to now, soon to be corrected apparently - despite claims from the start that it was an « exact » separation), seems a paradox to me in a machine who’s philosophy is to model the whole chain, from amp to cab. However, it’s just my personal feeling and many Kemper users who don’t make their own profiles are pleased with that they found in the rig exchange, or from commercial profiles sellers.
My own Kemper backup of the best rigs available (again, commercial and free), from all genres/amp models, is about approximately 170 profiles (besides my own 150+ Axe II profiles). I tonematched 27 of these profiles, those I like more (Fender, Marshall, Vox, Morgan, Mesa MKII, Diezel, Dumble, Fuchs, 5150, Bogner…), to use them in my Axe (and sonically these tonematches are at least as close as my Axe profiles are to the original Axe presets). I kept only nine of theses tonematches (I will need to redo some of them for firmware 17), just for variety ; I don't really need them. Now, the interesting thing : the tonematch procedure requires the user to match the Axe amp model by ear first. When I did it, the thing I noticed is that all the 27 profiles has a common sonic signature, a sort of compression/sustain in the mids which, although very pleasing, is quite strange, considering that a Mesa, a Dumble, a Marshall, a Diezel or a Vox are very different amps…
One good thing with the latest firmwares is that the bass response got better ; it used to be my greatest gripe