I have one tie cord and tried it out.. I dont like the way my roosters tug on it and pull their legs. And its a pain in the butt to get them on and off it.
I want the drop pens just move them onto grass or into the sun on cold mornings. I figure its easier than tie cord.
I may just do a few simple round pens. I have extra fencing.
It takes them a little while to adjust to the cords, but they soon figure it out. The nylon hitches can get a little tough to move, but I have seen some thin nylon cords as Havoc suggested with just a slip knot. I haven't tried those, but they look pretty simple. I am like you, would rather see the birds free ranging, but that is not always possible.