I tried mine at band practice the other day and it roars. I was playing my Jazzmaster through my Crate Power Block into an unknown studio 4 x 12, it had an awesome heavy overdrive tone with great toneshaping options thanks to the treble and bass controls. The bottom end is awesome, I had the bass set to just over half way and it sounded really deep and fat - no wonder Buzz from the Melvins loves it for guitar. It won't really do nice lower OD type sounds, I think it'll probably only work for heavy, noisy stuff which is what I want it for. One downside is that it's a bit noisy, but I can live with that.
I think Ends mentioned recently that due to the clean/OD mix (balance) control there is always a bit of clean guitar that creeps through into the sound, but I find this works quite well - it seems to add a bit of focus when picking strings rather than playing power chords. The pedal has tons of sustain and seems to be a bit more of a fuzzy distortion than an OD, I think it would be a bit much for my liking on bass.
Yeah, I tried it out with my Jazzmaster before I sent it off and it seemed to be more articulate than most overdrives in terms of hearing the individual elements of a chord rather than just the mushy buzz you often get where it's mostly the root notes. Glad to hear it's working out for you.