I used a pop up blind last season for the first time. I set it up in a field next to another, larger bush. I had deer from 20 to 80 yards and not one of them paid any attention to the blind. Except the one that heard me pull the hammer back on my pistol.
Twice now though, I have had a deer pop out at the closest point to the blind. One turned and ran as I was trying to get in position for a shot. The other one casually walked back into the woods. I think they might hear me moving or smell me though. I don't think the actual blind bothered them.