I have a 4*4 blind and it stinks. It is difficult to get the gun out the windows quitely. There is no way you could have your girlfriend in there with you unless she sits on your lap.......
I also have one that is 6*6. It is perfect. Two people can comfortably sit in itand there is plenty of room to quitely position your gun. There is even enough room to draw a bow. If you do want to bowhunt, you will need to be very precise about window placement and hieght. Mine is tall enough that I can shoot a bow standing. Six foot is probably to low for that.