ceramique is a breeze to apply to AMD CPU's on top of being non-conductive. Just stick a small dab on the core, set the heatsink on, give it a couple 2 degree turns and clamp it down. Don't have to try to get an even layer over the core, which makes it nice and quick. Only "time consuming" part is rubbing it into the heatsink, but even that is a simple and pretty quick.
The biggest reason I prefer ASC over AS3, is because its non-conductive, and any accidental "drips" or whatnot on some electrical components won't cook your stuff. For this reason alone i'd buy it over AS3 even if it didn't perform quite as good. A working machine is more important to me than 2-3 degrees.