90% of responses will be FOXPRO. But remember, coyotes have a good memory and many will not respond to sound that has led them to wild fellow who starts shooting. Point being, if your area has been hunted much the foxpro may not get the response you desire.
Also note that Foxpro has several hundred different sounds so the chances are the coyotes that you are calling that heard a Foxpro and survived did not hear the exact sound that you might decide to use. It's simply the fact they were duped and figured it out quick enough to survive and now they are wiser no matter the sound enticing them. IMO These are both top notch products with good CS that will serve you well.
I to own a fox pro and other ecallers, however I find they work best early on. Then come mid/late season I'll go to all the local stores and write down or take pics of what is being sold. Then, get online and buy something different and it seems to pay off.....need to keep them guessing or we just educate them. So I agree with some responses above