Having a preventer is good to use on long downwind runs. We'll sail ddw when the conditions, especially the seastate, make it more comfortable. Our big main vanged/prevented to the rail is a real workhorse, with a small poled jib, or just alone.

But it's not worth rigging our preventer for short sailing. I don't know if one would work on our long boom. A good idea though , I'll give it some thought.