I'm not sure if you know of the fan clutch differences. There are thermal and non-thermal clutches. The thermal clutches do a better job of being sensitive to engine temperature and ramping up speed as the engine heats up. Either will cool the engine at stopped or slow speed. The thermals are more efficient. The HD clutches are for a fan with a deeper pitch. It should tell you that in the specifications. You can run them with a shallower pitch but they don't cool as well like that. They cool fine, but they are designed for higher cooling capacity you get from the fan and clutch. As you have observed, they sound like a hurricane.
If you go to Hayden's site, they have a fan and clutch specification tech sheet that can be very helpful in picking the right setup for your application.
EDIT: I wanted to add that I am using an HD clutch on one of my cars and it does roar initially, but that it goes into more of a freewheeling mode after a minute or so.
