I used to run mine in parallel with an OC-2 using an LS-2 to blend them and it did sound good. I had all three of them stuck in the loop of my Meatwad and I remember the first time I switched on that combo in my first rehearsal with a new band, the singer turned around and yelled "Play more like that!"
Tracking... As I remember it wasn't as good as the BMS, but it's not far off. And it's analogue so there's no latency at least. Definitely ask Mario about the low end if you're thinking about ordering, because a bit more beef would really improve that pedal.
Speak Onion's got one too, or had one, maybe he can offer his opinion. Haven't seen him around for a while though so it might be worth PM-ing him.
Yeah, Pulse Syth doesn't have the most low end, and blending it with a sub-octave (I used to run pulse synth-->Octron) makes sense, but I don't think it's that bad. You just have to keep the "pulse" set so that with the depth off, you get the full 50/50 square wave, which has the most beef to it. Then when you turn the depth up, you lose a bit, but ever time the LFO gets to its minimum value, you have the squarewave and all your low end. Also, I always use it with my MAM Warp 9, and that beefs up the low end for me. I don't really like the Pulse Synth wihtout a filter. I actually just used Pulse synth on an improv track yesterday (dude playing a machinedrum by hand, me playing bass), and I was way happy with the tone. I'll try to remember to post up the track when it's released.