After 40 years of coyote hunting we still use mouth calls. They work just as well as electronic, they're cheap, and they are easy to carry. Two or three on a lanyard around your neck is simple, and provide a variety of sounds. Electronic calls have only one advantage, and that is the "distraction" from your position that they provide. I like hunting in pairs for the pure companionship, and because it allows a set up where one calls from concealment, and the other can cover approaches that may be used by cautious coyotes. Electronic calls work, of course, but the cost and inconvenience makes them just not worth it for us. Of course, we walk lots, so that influences our choices.