Fulltone OCD? Hmm, not so sure - got this from their website:
Q: The OCD is huge sounding, wide open sounding, why does it make my other Overdrives sound like there's a blanket over the speakers in comparison?
A: Because 99% of all pedals use clipping diodes to achieve their distortion, and the net result is you are lopping off the upper frequencies (harmonics) and most of the lower frequencies, leaving mostly only Midrange.
He says that as if it's a bad thing, and I guess if you're using an OD pedal as part of the tone stack than it is, but the use of a Tube Screamer for high-gain amps really isn't to provide any extra gain (hence having the drive almost all the way down), but rather cuz of its filtering effect that thins out the unpleasant flubby lows (and I've never played an amp that benefitted from it as much as a Rectifier!). A TS7 is only $40, worth picking up I'd say!