I have not used one, and I dont think that I could.. I just dont see how it would really work, I feel that it would keep falling over and it would be very uncomfterbul.. Im wondering myself now what others have thought or have used them.. Try going to cabelas.com and typing it in. You can read other's reviews that way.
"If I pull the hammer and shoot this young buck, he's dead. But if I pass on him, the next hunter might not shoot so straight."