We started using the DSD brand decoy about two years ago. I would not say a decoy that expensive has helped me kill more gobblers but I love watching the real hens react to it. The hens that like it stay around longer and those that do not like it will attack it. Fun to watch on a slow day.
As JW said, placing them in a location that will keep you out of the line of fire from another hunter is priority one.