Over the years I've had great results with any grunt call. Then again I've had no results with grunt calls. I believe it depends on the mood of the buck at that time. Never have had any results from a doe call until 2014 when I turned a nice buck around during the rut and he walked right to me. Then I blew the shot.
At times I've had great results with horn rattling. The 2013 buck I shot was within 5 minutes of rattling and 2 buck came looking but the big 8 pt. didn't make it out. But at other times I've seen bucks and no amount horn rattling, grunting or doe calls will turn their head. Jut have something else on their minds.
So what am I saying? Deer grunt calls, doe calls (the can). and horn rattling all work at times, but not every time and I will continue to use them.