I just wanted to update this a bit and add a more complete description of how I installed this. If anyone disagrees with any of my methods please do not be shy. I'm willing to find a better way. I was asked some questions elsewhere and would rather have this all in the thread where it can be referenced:
First off, download RealTemp and get the numbers from that. This seems to be the most accurate temperature measurement for 45nm cores currently.
If RealTemp reports the cores at 36 or above that's clearly a bad sign, if your room temp is reasonable. If you are in a 30c room, then 36c would be real good
I used AS5. I did not use that exact method. Are you sure it was AS5? Mine was more silver than black.
Here are the exact steps I used to put on my Xigmatek:
I used a one-sided razor blade like this:
http://www.doityourself.com/invt/1995133
I first held the base of the cooler up to eye level and pointed it towards a light source. I then put the edge of the razor onto the surface of the base, moving it around and looking for places where the light shone in-between the razor and base.
Obviously, there are grooves between the pipes and aluminum. These need to be filled -- not because you want the contact in those areas, because the paste will be too thick there for good heat transferal. No, you want those filled so that they interfere minimally with the thermal paste you apply in the following step.
If there are OTHER inconsistencies you find with the razor method, consider lapping or, if serious enough, getting a replacement cooler. I did not feel my cooler needed any lapping.
Before applying any paste, attach your hardware. I used the bracket kit, which I recommend. Push-pins suck.
Filling in the grooves:
I placed a pea sized (small pea, but ya, really) amount of AS5 onto the base of the Xigmatek. I then used the razor to work the paste around, completely filling in the grooves. This takes a little work to get just right. You want the grooves filled in, but no excess on the base anywhere once you are done. There will be some natural "mounding" of the paste that is in the grooves... it will stick up above the level of the base just slightly. Try to minimize that, but you will always have some.
The razor works great on this step to create a flat application and scrape off the excess.
This next step is where I differ with some other folks.
Use your AS5 syringe like a pen and draw three lines down the center of each pipe, not the aluminum. Each line should be about 1/2 the total length of the contact surface. These are thin lines.
Now it's time to mount. Please note that if you got a hair stuck in the paste of some other foreign object between the two surfaces, you are probably hosed and will need to start over.
Obviously, the cooler should be placed gently and precisely so the the bolts line up with the holes. Once in place however, you should gently ROTATE the cooler back and forth. Note that the design of the CPU holder and the cooler will only let you rotate the one or two degrees. That is fine. Do this at least 5 times, then bolt it down.
Do not tighten the bolts clockwise or counter-clockwise. Use a 1-3-2-4 type crisscross pattern and make three or more passes. Never tighten one screw down all the way without first having the others beginning to tighten.
I hope this is of some use. None of these ideas are original to me, just gathered from around the internet and especially here on these forums.
My E8400 is currently OCed to 3.6Ghz. RealTemp shows the minimum core temps at 28c and 30c... they generally run about +7c over ambient room temp.