have had success with a Johnny Stewart call this past year, but the thing was only around $10. perhaps it is that i am using this cheap call with limited sound options that i have not been able to attact that many coyotes. i am not in the market for an electronic call, but am in the market for higher-quality calls. i live in west michigan, so any other callers from the area please feel free to add on.
My philosophy seems to be if it makes noise I buy it. I have predator calls from many manufacturers among other calls. If you are just starting out you'll find that closed reed calls are easier to learn and blow with consistency. Practice with any new calls you get. Remember, an amateur practices until he gets it right, and a pro practices until he can't get it wrong.
I like calls a lot and therefore buy a lot of them. If it looks interesting I'll try it. I have diaphragm calls that I can do distress noises or yips with. I use turkey calls on occasion, even some bird calls. I have yet to venture into some of the "custom" calls or the guys out there making calls on their own. I'd like to start getting some of them into my collection.
I have a bunch of older Circe calls and love them. I use a diaphram for howls. Not sure about how the newer circe calls by lohman work but I would say give em a try. There really easy to use and hard to screw up. But like was said earlier practice a lot.