Jim sells C4s now.
Regarding sticky cams, I climb regularly on Met TCUs, DMM 4cus, single-stem Camelots, and aliens. I've had the most problems with the TCUs. But I imagine it's more of an issue of the type of rock, how careful I am about keeping the cams out of the dirt...
I've had some issues with TCU's getting sticky as well. Boiled, cleaned em, lubed em, workin great now! Never had any problems with the DMM's, or the camalot's i've borrowed. And while I didn't like the older camalots the new C4's seem pretty swanky! The old thumb studs just always felt squirly to me.