A bit of background- I bought a Kemper Power Head right when they came out a few years ago. Last year, I realized that I'd used the built in power amp exactly one time since owning it & wanted to try something new / sell it to someone that would make better use of it. So, I sold it and bought an AX8.
All I can say is, it's amazing how much less you play guitar when your rig is daunting to configure. I found myself avoiding the whole situation just because I didn't want to have to hunt around in AX8 Edit to find a tone I was satisfied with.
A short pro / con list:
.kipr files are only a few KB each, so I suspect the current Kemper hardware to stick around a good while longer since it doesn't have to model / calculate every component of a tube amp.
To this same point, I never have to worry about running out of CPU, which the AX8 did very quickly.
No lag when switching between presets / scenes / effects.
We just got an editor (yay!)
We just got great new reverbs!
Playing feel and right hand nuance is much better.
Ergonomically terrible. I hope Kemper never releases a floor unit for this exact reason.
Playing "feel" is stiffer / not as nuanced as the Kemper. I feel like this is related to how easy it is to access the Kemper's "Clean Sense" input level adjustment. Finding the sort-of equivalent to this on the AX8 isn't nearly as easy and it doesn't have as much of an impact on your playing feel.
Scene / channel switching is very slow for a dedicated foot controller.
AX8 edit looks like it was written for Windows 98.
Footswitch assignments were more confusing to configure than they should have been.
Knowing that it will most likely be replaced by a successor very soon, probably this year.
No headphone jack meant every time I wanted to practice, I had to fire up the AX8 as well as my audio interface.
All of this is annoying, BUT the biggest issue with Fractal gear is this: If you buy a commercial preset of some sort, then run a firmware update, it completely negates buying that preset because the sound can change drastically. The Kemper's sound, however, remains exactly the same, update to update. Once I realized this it pretty much killed the AX8 for me.
And with all of this, I feel like my timing for switching back could not have been better. I just got back from NAMM, where they got to show off the new editor, new reverbs, new cabs & Kemper Cone. What a time to be a guitarist and especially a Kemper owner!