I do on vh4 and einey. To me it's not much different than turning the amp down. For best results you will want lower ohm pedals. IE Ernie Ball for active guitars. (25k) Olaf said 10k would be better, but not that noticeable. I use EB VP JR active.
I run one, but I use it as an attenuator. You'll get the same tone but at a lower volume. No gain characteristics change, just volume. So you can get that full saturated sound at a MUCH lower volume. It's not like lowering the volume on your guitar which can change gain and tone as you are change the level from you guitar before it hits the preamp section. I've been meaning to ask the board if this can do any damage to the amp in anyway. This is my first post and I was actually going to ask a similar question.
P.S.
I just got a Einstein (100w w/ mod) about two months ago and. . . . . WOW, Diezel really is in a class of it's own. I will ALWAYS have a Diezel in my arsenal.