Has anybody ever used this instead of thermal grease?

Has anybody ever used this instead of thermal grease:

http://www.newegg.com/Product/Product.aspx?Item=9SIA3TW18W4998

The stated thermal conductivity is higher at 6.0 W/mK than most thermal grease.

I have used these types of pads for work designs and they are less messy with more consistent application than any sort of thermal grease. However, never for anything with as high of a power density as a CPU (power transistors, voltage regulators, etc.)

I am wondering if anybody has ever used one of these to mount a heat sink to a CPU?

I believe this was just brought up about 2 months ago. If I'm not mistaken the consensus was that they're to thick for CPU's/GPU's but are great for memory, vrms and the like.

I'll look to see if I can find the other thread...might take awhile though.

Not I, but if you decide to play with it please post up your results. And Welcome to OCF!

It won't work.
Just get regular TIM

Why won't it work? They come in different thicknesses (1.5 mm, 1.0 mm, and 0.5 mm).

I imagine .5mm is still far thicker than desired. TIM is there to fill in the tiny gaps between the heatsink and the chip, not to be a full barrier between the two.

Yes but TIM is probably 1/100 of that. It's put on to fill small gaps/scratches in the metal too fine to see. You still get nearly metal to metal contact.
Thermal pads are meant to take up lager spaces and avoid contact with metal and sensitive parts. It's meant to conduct heat yes but not in the same way and the distance plats a huge factor. If you were dumping something out of a wheel barrow it's easier going to the end of your laneway than 2 miles down the road. So the heat from the CPU gets "backed up" for lack of a better expression and your thermal transfer material starts to act more like an insulator.