Hi there, and

!
I actually started a
thread about this in the summer, along with a poll, and got some really great answers if you want to check it out! Most people voted yes, but the second most-voted answer is "it depends".
My set up with chickens is a lot different from yours- we now have about 70 chickens and 4 guinea hens. We live in the "country", we have 18 1/2 acres and are along a dirt road. We don't have a large fence to keep them in.
What we have found so far works for us, is we let them free range sometimes when we are able to watch them. There are LOTS of predators where we live, hawks, opossums, foxes, bears, owls, you name it. We do not want them to get grabbed or go into the road when we are not watching, so we are pretty careful about it.
We are outside a LOT throughout the spring, summer and autumn so we can watch them a lot. We start out letting them out about an hour before dark to train them to come in at the right time. Then we slowly increase that time to let them free-range for longer.
Even though you do have a fence, just keep in mind chickens can be VERY good flyers depending on breed. So if you don't have a top on it the chance is there that they fly to the top of the fence OR, depending on where you live that a predator could swoop down in the fence.
So I guess the short answer is, it depends on your environment and what you are comfortable with. I probably would if it was in a small backyard where it's easy to keep tabs on them all day.
I hope this helps
