what are your thoughts on "pop" up blinds? I bought one this year and I am just not sure about them. do you think youhave to leave them up for weeks prior and do you think they spook the deer? I have been hunting a farm that doesn't have trees big enough for my stands. Twice deer have looked right at the blind and went back the way they came? I brush it in to the extent I can without making a bunch of noise. What do you think?