I don't have either so I can't comment on the differences in the particular units. However, I have a cousin who does quite a bit of calling in Eastern IA and just last year they switched from Fox Pro over to primos and have had much better luck. A potential reason could be that everybody and their brother uses foxpro and coyotes could certainly be getting used to hearing the same sounds all the time. I'm not saying to go one way or the other with your purchase, just something to think about.