Well I just picked one up. Haven't had too much time with it, but enough to play and tweak the effects a bit. To answer your question directly, YES and NO. While you can set the parameters to the max, it really doesn't lose its usability IMO. Some of the presets are over the top. But at no time did I feel the effects were getting out of control. Honestly, I think the trick with using the Modfactor is combing other effects through it, Filter, distortion etc.
But it is polite

which I like. I would say its on the Sterile side, only because its not noisy. But that's why I suggest using other effects in front of it.
I liked it so much I am considering the Pitchfactor.