I don't think I've ever seen a Grind (including mine) that wasn't set at 1:00.

That seems to be its sweet spot.
That being said I do use it with my 2203 at times (when playing a LP Custom drop tuned to Eb) but still enjoy the good ole' SD-1/DS-1/BD-2 Boss stuff better with the Marshall.
My Orange Rockerverb SLAYS with the Grind. In fact if more Orange players knew about the Grind and how it takes the dark loose sound of them into epic metal brootz-land they would all have this pedal.
I'm a fan of the pedal, but the amp needs to be thick to begin with.