I suspect that most drag devices will work adequately well, with most boats, in certain conditions. While it's important to find a 'one size fits all', if such a thing exists, I think the emphasis must be on its being fit for purpose, which is to say that the device has to survive being out there for more then one storm, before needing to be repaired or replaced.
Fifty years ago, Voss's sea anchor was all the rage, but they invariably shredded if used in earnest for many hours. With modern materials, they could probably be made to last a lot longer, but at the end of the day it is chafe that is the big issue: chafe where the ropes come on board, chafe of the gear in the water. So far, none of the existing devices seems successfully to have solved this problem. For this reason, it may still worth carrying several long lengths of rope and a tyre, so that when the second storm comes along you have something else to deploy!
But keep up the good work, innovators all :-)