I broke down and delidded my 6600k with a razor blade (a little nerve wracking). The gunk that intel uses was very dry and 'crumbly'. I replaced the IHS with a grain of rice size ammount of Noctua NT-H1, the same TIM I use on the AIO cold plate. Prior to delid, my temps were maxing at 82c with P95 small FFT's. After delidding, the max temp was 63c. Pretty impressive and dramatic decrease in temps despite my skepticism.