Just went through a similar question with our new setup. Our birds are now free ranging during the day and doing well. I was concerned about them roaming too far and getting off our place and also area dogs, but they're staying in an acceptable area and our dogs seem to keep other dogs from coming on our place.
We did the same thing with an earlier setup and it worked well also.
Before letting them range, when I was still concerned about them being loose I built a pvc run that I could move along with our tractor. This offered them a pretty good area to 'range' in. I actually also used an older one I had built earlier and let them in both. In my view such a setup is best utilized if you're diligent about moving it, but I think it's a fine alternative and offers some of the benefits of ranging with the security of a run.
Daytime predators are not much of a concern for us and though many protest the use of chicken wire, that's what's on our tractor (they roost there every night and I shut them in) and we haven't had overnight problems, either at our new acreage or our much more rural previous setup. Our own dogs do seem to assist on that.
Good luck with whatever you decide.
