What I do is record the guitar into my RME Babyface's instrument in, then send that via SPDIF to the Kemper, and the processed signal back via the main XLR out to the Babyface.
If I record the Kemper directly it sounds fatter, and there's definite gain loss with the re-amped signal. For cleans there's no real problem but for distorted high gain sounds it's losing something, it's like it's 85% there, the sound is perfectly useable but inferior.
I have to use a coax > optical convertor by the way as the Babyface has these Optical ins and outs, and because the convertor is only 1 way at a time I can't go both ways using the SPDIF. I have tried the re-amp sens but not seeing a huge difference.
Thanks in advance!