I have an AxeFx Ultra, a Kemper rack and the AX8. They all have their benefits and nuances and I'm a fanboy of them all. If you get a great profile for the Kemper it's awesome. As you start to tweak it like a traditional amp (adjust drive/pre-, treble, bass, presence, etc), it starts to get a little weaker and doesn't behave exactly as an amp would. (I have a JCM800, Mesa Boogie and Silverface Fender Twin to compare). The AX8 is great from a portability standpoint and I find tweaking those parameters tend to react and be more amp like in its response.
So if you don't mind 100 different "snapshots" of the same amp, the Kemper works. If you have a single preset//profile and want to tweak off that, it doesn't react exactly like an amp so it might not be as fulfilling. The benefit of the Kemper is basically it's limitless and you never run out of amp models and don't have to wait for Quantum Rev 5.0 (hint! hint!). Your only limited to the size of your wallet to download commercial profiles (most of the shared ones are "ok"). In some cases, the amount of profiles can be overwhelming so it can be a double edge sword too. I initially was buying everything but decided to lock up paypal and listen to all the profiles I've purchased and found more than enough from clean to insane, vintage to modern.
I use the Kemper at home, take the AX8 to gigs and use the ultra as a backup. Britt profiles are great. He really tweaks them for live /stage volume so your home/bedroom experience might not be optimal.
I run all of the above thru a Matrix GT1000FX running thru a Xitone 1x12 cab (and FOH). No complaints. Sometimes you want smooth peanut butter, sometimes you want chunky. YMMV.