Pros: **Best rated thermal compound from the Toms Hardware aside from the ones that you had to put into the microwave to heat so they would spread properly or were not psyco-overclocker that even experienced builders would stay away from.
Cons: My last heat sync/CPU were lapped (sanded down perfectly flat) so the heat transfer would be perfect. After putting this new PC build together I figured I'd run it a while without voiding the warranty on the CPU and Heat Sync, and the temps have reached 50 degrees celcius on one core and 49 or 48 on the rest, so why would I void my warranties by lapping...? Although to be honest, overclocking may have already voided the CPU warranty, but most parts that work the first...
Summary: It's thermal paste. It smells bad, probably tastes awful (don't try it!) but it spread well under my heat sink and it seems to be working great so far. Consider adding these to your baskets when they're on sale... Never have too much spare thermal paste!
Pros: It's thermal paste, not much to say, it works.