From the demos I'm expecting to like the option with the switches all off just to add a little something. I often like a p bass with flats, but with some mid range nasal nastiness - like John Deacon's 'Live at Wembley' tone - that just seems to bump the harmonic content a little bit. Sounds a bit rubbish on it's own but nice and fat when the rest of the band are playing.
I will be trying the synthy suggestion though. I do like noises like that. I've tried lots of synth pedals and I either come back to separate pedals working together, or the good old Digitech BSW.