Rob, I dont recall ever hearing it before this year. I bought the primos roar and a friend bought the mad growl at the beginning of november just for kicks. I watched both videos and took the call to the woods. I was very hesistant to use it at first. I'm always thinking about the deer i could scare off that were headed my way.
Anyway on an evening hunt w/ a friend who had not seen the videos we heard the roar. It startedout w/ us hearing 2 bucks sparring. Then we heard the roar, which is a sound i'll never forget. We guessed the distance at about 100-150 yards. After that i figured i might as well try it. I wasnt able to call anything in that evening but i did have several does come in the field and they certainly didnt seem spooked.
In the next thee days i used the call two times each set. At no time was a deer in sight so i cant say if i spooked any or not. Anyway I guess i used it a total of 6 times in three days w/ 2 of those sessions being successful.
Like I said before, I believe I heard a full out "roar" that particular evening. It sent shivers up my spine and I showed the video to my friend who hadnt seen it and he agreed that it was exactly what we heard.