Yep, there's a difference, the Whitetail call will at times bring a w/t closer for inspection - a mulie call will leave you sitting in the bush making noise! Try raking horns for both as it tends to have better results, whitetails will come out in the open if you can sit still enough, mulies will just come to a brushline mostly. Of course there will be giuys that claim to call in mulies all the time (Al) but don't count on it, more than anything you will just give away your location and blow your cover. Where the call really holds value is in stopping a moving animal, I like the coyote whistle for that though. Good luck.