I feel the same way both for both day and night use. When it works, it typically works too well and coyotes attack the decoy. If using a shotgun great because you want them close, but not many people use a shotgun at night. I have also seen coyotes spook from the motion.
To me, I like to be able to control the coyote by the use of the sound, as the decoy adds a major unknown to the setup.