I've been looking for ways to make the PB sound a little more vintage and less polite. An easy way to do this, which is not well documented in the manual, is to use the Pitch Accuracy setting (hold Settings and turn the Fine Tune knob) and choose one of the Mild or Wild settings. This works especially well in Unison mode, where all six voices are stacked on top of each other and the loose pitch accuracy causes each voice to be slightly detuned.
For additional grit, you can detune the second oscillator slightly, or route the Voices source to either Pitch Global or Pitch Vco1/2. Then send both oscillators to the ladder filter, turn up the distortion, add some glide and filter envelope and sub osc, and you've got a very nice growly Moog-style bass.
This goes a long way toward thickening up the sound - in fact I wonder if a lot of complaints about PB sounding 'thin' might be due to people not having discovered this Pitch Accuracy setting.
