My loyalty to the Axe is 100% based on the fact it is the better tool for my needs. I tried a Kemper, thought it was pretty nifty, but there were many reasons not to change.
Much of the Kemper marketing is based on the "You can profile your own amps" - I'm sorry, this is utter bollocks.
No matter how good the technology is, there is a LOT more to profiling that just having some device (Kemper, or whatever else) at the end of the audio chain. If you look at the "mics" list in your Axe-FX amp block, there's $40,000 worth of different mics in that list. That's what you need to start doing proper profiling (plus proper pre-amps, plus a good sounding room, plus an engineer...) There are guys out there running IR businesses, and trust me, they're not just shoving an SM57 in front of a cabinet in their garage.
Hence truly getting the most out of a Kemper really means trawling the web looking for good quality profiles, and frankly I haven't got any time/desire for that. The Axe comes with everything I need.