a lot of guys will get to a spot and use a howl to see if they are in the area, they hear them then try and set up on them, often the coyote is already moving to you and you to it so success rate would be low. if you are hunting coyotes in the day, if you could ride around the night before with the siren and listen you would have a better chance of getting one the next day because you have narrowed down the area.
Buckwheat - i fooled around a lot with the decoy last year and had zero success with it, it really doesn't fit into my style of coyote hunting. now fox that is a different story and the hawks and owls love the decoy.
Whitefeather - i hunt in Luzerne, Wyoming, Columbia, and Bradford Co's. I wont target just coyotes until after the new year, you could wait until then or you can come up before then, but most coyotes at that time are not targeted but we do call them in on fox sets.