Well, it would be more convenient for me to have her off leash while doing chores on the farm. It would also be more fun for her if she could hike off-leash with me. And dragging leads are such a hassle, they get stuck on things, or tangle in barbed wire, or scare the horses (I guess they think its a snake lol). I definitely will not do it until I'm sure- as you said, it could turn out to be a huge deal. However, I think in my situation, and with a wicked-high energy border collie/spaniel mix, the benefits outweigh the risks- once she's trained.
Thanks for the input, it's been helpful!