So, there’s some good info here and some interesting ways to use the Kemper.
The quick answer is the Kemper doesn’t suck
I have a Powered Rack. I’ve profiled a few of MY amps that I really dig and find that these are the profiles I use most. Also, I have purchased a few profiles that are great as well. When I use the Kemper for a LIVE show, I run the Kemper’s Main Outputs directly to the FOH and then I also have a 4X12 cab onstage for myself and for stage volume for the band and audience. The cab is run out of the Speaker out, with Cab OFF on monitor, and the monitor volume is also adjustable. No chance of blowing the speakers AND any changes made to the stage volume don’t effect the FOH volume.
IMO, if you have amps that you LOVE the sound of, you can profile THAT tone and be extremely happy with the Kemper. Also, as I said, I’ve purchased a few great profiles as well. Rig Exchange is a great place to start and if you have the time to search and audition profiles, you can find good stuff there.
On the other hand, my Axe III is a different tool. I can create presets from nothing and it will simply sound great. The Axe has very accurate amp models and plenty of cab IR’s built-in. The effects section is vastly superior to the Kemper’s, although I really like the recent verb and drive updates from Kemper.
There may be a bit of a learning curve with the Axe III because it has some truly useful options that one must learn how to implement correctly for maximum benefit, yet the results are truly spectactular.
I currently use the Axe III for a majority of my live shows and have had BRILLIANT results.
Both are AMAZING tools for live and recorded music.
To the OP, again...if you already have the amps that you LOVE the sound of, the Kemper can really make sense.
I really like the idea of having the GREAT tones of MY amps in the box.
For me, I just gotta find the time to spend profiling them all
Also, if you record a tone from your amp, LOVE IT and want to come back to that EXACT tone or be able to recreate in a LIVE setting, just profile it and have it in the box forever. This is a VERY useful way to use the Kemper as well.
Best of luck