I actually haven't played enough with the pitch shifting. The built in Distortion engines are good enough for me if I want to combine pitch shifting with dirt.But if it’s after the dirt, you can’t really get a distorted synth tone, right? You can mix in distorted bass but the synth is always clean. Hmm, maybe keeping them separate could be a good thing.
I like using the Envelope options, with the filters on and off, the LFO options, and the sequencer each after my dirt pedals rather than into them. For me using the envelope controls with my other fuzz pedals has opened up a lot of synthy distorted tones but a different kind of synthy. So far that's my main reason for running it later in the chain. If you like "synthy fuzz" just wait until you use the envelope controls in the C4 to shape the attack and decay... Likewise the fuzz into sequencer, fuzz into tremolo, etc sound better than vice versa.
For reference I run a Damnation MBD-1, EHX Black Muff Pi and Mastotron in addition to my Aftershock so you know what I'm working with.
I'm preeetty sure when I start paying more mind to the pitch shifting and harmonizing options I'll want two C4's...

