I gigged with a mkii for a long time in 2 bands, one similar to older Gojira style and another Sludge. I absolutely loved it. It has a really good clean channel. The 2nd channel is pretty underwhelming for the Marshall sound imo. You can get some nice chunk out of it, but I agree with what's been said about the hi-fi sound and lack of bloom. I could never get it to sit right in a mix. The 3rd channel is pretty much all I used it for. It's pretty much the boosted recto sound no matter where you dial it. It still has its own flavour, like a touch of 5150, but I couldn't un-hear the recto.
I got mine used and some dummy oversized the fuse by 5x and she got scorched. I'd get the thing serviced at least once a year the whole time I had it. H&K's customer service swore me off the company.