You never know with decoys. My experience is mostly positive. Matt1953 and I were out a couple weeks ago and had a hard charge come barreling in, try to eat the decoy, knock the Shockwave off the yucca, then turn around and trot off so Matt could shoot him. A couple months ago I had the same call with same decoy going and had a coyote come running in only to turn inside and leave at Mach 1 as soon as he saw the decoy. Huh. Usually though, the decoy seems to help, or at least not hurt. Watch out for great horned owls though...