I am using a Maxon OD808 in front of the Kemper. Tried using it in the stomp section via the loop but it lost a little something. In front it works great.
I tried a MXR 10 band in the effect loop and it sounded great though the level had to be kept down (way down, I couldn't run it near 0db) or it would overload the return causing pops and for the sound to cut out.
Using a BBE Sonic Stomp in the effect loop was ok but I could not set it above 5 on either setting or I would get popping.
Edit: Reducing the effect loop volume helps with the clipping.
What are your experiences?