It has been my experience that expensive and exotic heat sinks are over
rated. I've used them, but get the same performance out of heat sinks that are composed of all copper fins with aluminum blocks. I always chunk the thermal paste that comes with the heat sink and use high
silver content thermal paste. Never had a problem with one exception:
We recently go an athon 64. I used a good mid line heat sink with silver
thermal paste. It got hotter than I wanted it to (Although, the system
did not get unstable crash). I put an oversized fan on the heat sink and
that solved the problem.
Best regards
Marvin Dickens