I have used them with success in the past. They do keep you warm on those cold morning hunts as well and hide movement. When you get everything setup, practice raising your weapon and go through the shooting motion. Make sure your elbow does not brush the back of the blind, your gun does not hit the front, your feet do not bump the seat you are sitting on to make noise, etc... Also, do not open all the windows. Just the ones you thonk you will shoot through. The deer can silohette you if the back windows are open and any movement will be seen. I only open enough to shoot through and zipped them closed when I am not there.

Also, if your using a powder that smokes a great deal, make sure your barrel is outside the window when you shoot. If not, it will fill with smoke and look like a Jamican hooka lounge when you finally open the door.