You're not going to improve temps 10 degrees just by using IC Diamond instead of Arctic Silver or any other thermal grease. You probably had mounting issues.
quoted for truth. there is not a single thermal compound out there that is 10 degrees better then any other. all benchmarks or tests run on TIMs end in a victory being declared based on a 1 or 2 degree difference, which is well within a standard deviation.
its great that you lowered your temps, but do not declare this to be a super magical fantastic thermal compound because of anecdotal evidence that can easily be explained by other factors.