Had no choice the thing was running hot so the fan was always on high, cracked it open and found out that sony uses cheap thermal paste.
Coming from someone who used to build and repair computers, the difference between your run of the mill thermal grease and so called "high end" AS5, or arctic cooling products is next to nothing.
The amount of heat that is actually transfered through the paste is very small. What really determines how effectively the heat sink disperses heat is how smooth the surfaces you are connecting are. Slapping a magical paste on them is not going to do anything but put a hole in your wallet.
It's one of the biggest misconceptions in DIY computing. Here is a good article to read.
http://www.dansdata.com/goop.htm
"If you think any particular grease is going to cause your CPU to run more than a few degrees Celsius cooler than any other grease, though, then assuming the grease is properly applied, you're dreaming."
Keep your heat sinks clear of dust, that's pretty much the best thing you can do in terms of heat prevention.