Well the Fenrir is amazing on LGA but not so good on AM2. The Scythe Mugen 2 is great for AMD but not so good on LGA and so on.
Honestly, I am beginning to notice this in Custom PC where they review about ten coolers a month (boring, but I suppose it gives them something to do
) and any cooler that is brill on LGA usually sucks on AMD.
In fairness though I know that the Intel CPUs are where it is at atm. So hardly any companies are going to make a cooler based around what it does on AM3. They're all going to go where the popular money is at I guess.
I'd be interested to see the insides of these CPUs and see how the core array is arranged