FYI neither of those are highest performers. For a listing of heatsinks ranked by cooling capacity when there stock cooling fan is removed (so they all are cooled by the same fan) see the following link: http://www.silentpcreview.com/article30-page1.html

Logically 775 can be used in i7 also they have recently reviewed a cooler that was made for i7. Personally I would only do WC if I am OCing and thus have not studied the HT with regard to OC ability but rather silent cooling ability for my HTPC that I am making this summer.

I would like to add that mounting systems tend to make a big difference in air coolers on the hi-end. This is because the HTs them selves tend to get very simular leaving major performance differences up to details such as contact pressure and the construction methodology of the HT.