For what it's worth, because of the cost and limited quantity of the AS3, this is what I did. I used AS3 on the connection between the GPU chip (9700 Pro) and the ZM80A (don't have a ZMNB32J), then used the supplied grease on the connections between the plates and the pipe. This seems to work very well, but I can't say whether the AS3 has made an improvement. (I like to believe it does
) Both plates (top and bottom) get hot under load, and it has never crashed during benchmarks or games--so it's definitely doing its job!
I personally couldn't justify using AS3 on all of the connections because of the total quantity and diminishing returns. I think its primary benefit is between chips and heatsinks.