I let mine out but I have a fenced area although it has no top and is only 4 feet tall. They can get over it but never tried until today. Lucy took flight but before she got over I snatched her down from my picket fence. I clipped both her wings today. You can't let them run over other people's property and tear up their gardens or yard or leave poop on their sidewalk. A fast way to irritate your neighbors.
I didn't let them out for two months and now I let them out once or twice a day for 2 for 4 hours depending on how long I feel like being out there (with some fast dashes into the house for a drink for me and a small treat for them). In my dream world I would have an enclosed aviary (lol) but my fenced in area is 30 feet by 50 feet with tall trees, so closing it in completely across the top is not an option.
If you start to let them out I would do it just before dusk in 1/2 hour increments. My chickens go up their ladder on their own when it gets dark and then I lock them up for the night and close up the coop/run as well. Some days I don't let them out at all if I will be away and that is just life. They have plenty of room in the coop/run combo but they do like to be out and about.
I was a bit nervous when I let them out the first time as they acted a bit crazy with the new found freedom and starting running all over the place at top speed and flapping their wings! I thought - oh my gosh - I won't do THAT again, but I did, and now we enjoy our time outside the coop together.
I love watching them chase flying insects, scratching around in the leaves, jumping up in my lap (only one does that) taking a big communal dust bath, and how they watch and listen to all the other birds around in the woods, people, sounds of cars, etc.. It is really funny to watch them turn their head completely sideways to look straight up. When crows fly over head, mobbing a hawk for instance, they all run under my chair. I guess I am their safety net (or my chair is). Chickens are 100 percent food motivated. I'd like to think they like me but they like me because they associate me with food. That is a good and bad thing. It is easy to trick them into where you want them to go, but on the downside, you have to watch when you are walking into their yard as they will trip you up being underfoot and obnoxious.
I do think it is a matter of time before one goes over the fence but if you keep them busy they soon forget. I shake their feeder, or pull a bag of mixed seeds out of my pocket, or some grapes. I only have three chickens and two follow me around and go in the tractor with just my me going over to it but one would rather not, and instead continue to scratch about. She knows the deal and I have to attract her first sometimes with a delicious treat and if she goes in the other two are easy. I can pick those two up but not Rita. She is more independent and won't be touched or held if she has any say.