I have one, and I gig steady with it in a few different bands.
I think it sounds great, and always get compliments on my tone. I put all JJ tubes in mine, and they definitely sound better. I don't find the sound sterile at all. I think of the H&K stuff as a blank palette, and it's up to you to make the sounds. I think the amp screams. It sounds better than my 6505, and Triple Recto to my ears. The delay and reverb are good. The mod effects are just ok at best. They work in a pinch, but I use a G Major in the loop.
It's an absolutely fantastic package that has great tones, great options, and portability. YMMV.