First, it helps if conditions are conducive for free ranging. If you don't have a good LGD to mind the chooks for you while your back is turned, you are probably asking for heartache. Also, a good perimeter fence is helpful, but not from air attacks (the dogs and a good roo are deterrents for this).
My chickens are healthier, more sleek and glossy, and just all around happier, if one can use that word about an animal. Fresh air, green grass, sunshine, fresh forage and bugs, cool, clear water? Who wouldn't prefer that over a bare dirt run, a dim coop with no chance to escape a bully, no fresh food?
No fighting, no picking of feathers, very harmonious living for them. They eat less feed, are parasite free, no illness to date (have been doing this for around 8 years total), no losses to predators.
The absence of predation is largely due to the fact that I am not located within a hundred yards of the nearest woodlot, I have fence completely around our 2 acres, I have two of the best LGD around, a rooster that is wiley and protective. The only predation I've really had was 2 chicks eaten by a black snake this spring...and those birds were in a brooder at the time, with no chance of running away, as they would in a free range situation.
The people who free range feel like its a good trade off to lose the occasional bird to predation if their birds live a healthier, more calm life-style. If you do not take the proper precautions to protect the birds and you lose some, you may change your mind. If you do have all that in place, and you still don't mind the occasional loss, then freeranging should be alright for you! Good luck!