I ended up using both MXR/BAR and the PSA-1 together on the record.
The end result was this, which I actually just put up on the RMM board:
[ame]http://www.youtube.com/watch?v=JIhOPyUbmQ0&feature=related[/ame]
More recently I've reamped the MXR into an Ampeg SVP-CL and then ran that into a bass cab impulse. Worked amazingly well. That CD has yet to come out though.
@UtopianCrux: Sorry I missed your post months ago. No idea what the settings ultimately were, just that there was a blend between distortion and clean, which favored distortion heavily, and that the gain was cranked (too high =D). The pedal does definitely bring the uglyness.