I've had my Kemper for just over a year and I've come to the conclusion that it's just not sounding great. I've spent hundreds on professional profiles and have used the Kemper on every project since it was purchased, with multiple guitars and players. I just finished a project where I opted to use a Neural DSP amp sim instead because it simply sounded better.
I am running the Kemper into an Apollo Twin via SPIDF and capturing the DI and STACK sound simultaneously, with the clock source set to SPIDF and the sample rate matching my session at 48k. I've compared the sound of the raw DI coming from the Kemper to the HI-Z input of the Apollo and the sound virtually identical.
So I decided to do some experiments. I purchased an Orange Rockerverb from a German profiler that sounded amazing in the youtube video and tried to recreate the sample track from the ground up. Note that I don't have the exact same guitar as the profiler, so I understand it will never sound exactly the same. He is using a telecaster and I am using a high end statocaster. What I am mainly concerned is the quality of the tone. Here's my results: