I only use the 52-11 on downhills for precisely this reason. I spend most of my time in the next lower gear, which is the 13t, I believe. That's on one bike with a Shimano cassette.

The other bike has a freewheel with a 14t as its smallest ring. A 13t (readily available on a Shimano freewheel) gives me an extra 4 gear inches, which means my cadence doesn't drop enough. On this bike a 50-11 would probably be high, too, but I am not familiar with the DNP brand of freewheel.

With the responses given so far (i.e., few have direct experience with this freewheel), I should buy it, roll on it for a few hundred miles, and come to my own conclusion.