I've been lucky enough to hunt with a couple different
folks that were good enough at calling that I'm sure
I would not have been able to tell they weren't the
real thing. I've also heard others that were easy to
tell they weren't real.
I'm lucky enough to hunt an area where hunting pressure is
light enough so that if I see a truck parked I just head to
another spot a couple miles away---because you really can't
tell which side of the road they are hunting on.