I haven't had any personal experience with the others mentioned here but i have with ASAT. On one ocassion I had a mature buck looking right at me as I was in a bare tree with no cover. The buck seemed a little concerned but not enough to spook or even be cautious enough not to get stuck with an arrow at 25yds. He's on my wall now.
Another time, a 2 1/2 yr buck came in from a direction i did not expect and i found myself being stared at at 15yds while only 6ft up the tree. Once again, i was out in the open with no cover. That guy is also on my wall.
What I haven't tried is sitting on the ground and trying to accomplish this same thing with ASAT.