MX-4 is the better product and it is also not electrically conductive, Ceramique2 is really no better than the original Ceramique and from talking to a Artic Silver Representative was really never marketed for the CPU crowd, it was marketed as a TIM for the air industry, with a long cure in time.
It was specifically designed not to fail under extreme vibration conditions, but you won't be taking off and landing your computer.
Artic Silver 5 was marketed for the computer overclocking enthusiasts, however it's long cure in time turns most of us away from the product.
That tid bit of information is something I can share here but could not include in the Thermal Roundup in my sig, simply because Artic Silver would not submit testing samples for the roundup, but did give me permission to include samples I already had on hand.
MX-4 is an excellent TIM, flows and spreads easy, it out performs Artic Silver Ceramique and Artic Silver 5, check out the thermal roundup in my sig.
Ryan