I bought the D7K last year. Unfortunately mine clipped noticeably on the clean signal (with passive J pickups) - which was really annoying. maybe mine was just faulty or maybe they are all like that.
If it hadn't clipped on the clean it would have been a really nice pedal. Not the same as a Darkglass B7K, which I now have ..... again, but in the same ballpark. The Demon D7K had a slightly more old school sound I would say in comparison.
Mine ended up in the bin though. It was no use with the clean clipping, I wouldn't sell it on and it wasn't worth sending all the way back to China.