I totally feel that this call(buckroar/growl)could and does work with several exceptions...

/1/ I think there is less potential for it in high pressure area's with low buck-doe ratio's and a greater population of younger bucks. I bought the Buck Growl from M.A.D. calls, and used it on a 2 1/2 buck last year, but he just stayed in the thick cover for about half an hour before moving off... I think I over called, but still with less mature bucks per square mile, there is much less of a chance where the deer might have ever even heard the sound in his liftime. In the Midwest where the deer herds are managed for high buck-doe ratios, and trophy bucks, i think it could have amazing effects.

/2/This call to the best of my knowledge is used by bucks mostly during and around rut, so you'll have to pick timing carefully. And I think it is important to realize that it won't work like majic, or even most of the time, although ihave no doubt thatit could just be the thing to tip the odds in your favour.
Gerard