Two years ago I bit the bullet and bought one (they are not cheap). I didn' t really know what to expect. The first time I used it was in your neck of the woods around Devils Lake. It worked outstandingly! For two days in a row, my brother and I set up seperately on the same large pothole. The first day I shot my limit of birds in the first 20 min. and my brother had only shot one. Every duck that came to the pothole came straight to my spred, even though my brother is a much better caller than I am. After I shot my limit, my brother moved over to my spred and finished off his limit.

BUT- three weeks later, we were hunting in southern ND, and it was a totally different story. Most of the birds that came by flared at the Robo duck. I had better luck when I turned it off. Lots of other people have motion decoys, so the birds get smart quick, especially mallards.

Over all, I would definetely say they are worth it, just don' t be afraid to turn it off if the birds are shy.