My take on this is it is extremely versatile. The eq section is really useful. There is no loss of bottom end. Treat the drive as if it were your gain, the level as if it were your master and those make sense. The voice is like another overdrive, getting a balance between voice and drive is i suspect, the trick.
Hard to tell from a recording but when you're in the room this adds an almost tangible thickness to the sound. It goes from grubby, through dirty and filthy to absolutely obscene. I homnestly can't imagine what overdrive sound a bass player would want that this can't do. Except fuzz. It's not a fuzz box.