I often get asked which calls I prefer for coyote hunting. To be honest, any Johnny Stewart Wildlife Call will work but let's break it down a little. Some guys prefer to stay old school and use hand calls, where you do the work yourself, while others prefer just to push a button.
Hand calls are easily packed and have alot of realism and volume, but sometimes require alot of air to make them work, and some movement. Electronic calls have a variety of sounds, adjustable volume, and don't really have any movement inolved to use. I personally carry both with me on each sit and choose which I think would work best for each setup.
Sometimes hunting more open ground the hand calls may not have enough volume to reach out far enough where the electronic would be more suitable. In other situations the electronic caller may be hard to hide, or maybe the batteries happen to go down hunting in cold weather. So I would advise anyone going predator hunting to have both hand calls and an electronic, such as the Grim Speaker 2, so that no matter what situation you have several different options for each setup.
I think the most important thing is that we as hunters do our best to take some of these predators to help out our other wildlife. Have fun, be safe, and keep the wind in your face.