If you've got the AS5, you might as well add it the first time. The thermal pad that comes with the stock HSF is actually quite good, but I would still expect the AS5 to perform slightly better.
Just makes sure to clean all the paste off reall well. I just used rubbing alcohol on mine and it worked fine.
Just makes sure to clean all the paste off reall well. I just used rubbing alcohol on mine and it worked fine.