I call it a win-win. I went without covering this new area and so far none of the ladies have flown the coop for greener pastures. I don't even think they realize there is no netting on the top - they are too busy pecking the ground.
I attached the pen to the permanent outdoor run by cutting a chicken-sized door in the run, leaving the flap so it can be closed when I want to move the fencing. But it is otherwise open so they have access to their food, water, nest boxes and predator protection.
Since they have been enjoying the fence area so much I purchased a second roll of the fencing - Green Vinyl Welded Wire, 48 in. x 50 ft. - from our local Tractor Supply and doubled the size of their 'free range' area.
The 4 ft. stakes that I use to anchor the fencing are easy to remove and hammer back in a different location. It takes me about 15 minutes to move the entire fenced area to a new section of grass, and the extended length allows for more possibilities as far as locations. I just always have to leave enough to reach back to the little door.
I think this will be very beneficial for the ladies - I am already seeing a slight increase in the number of eggs I am getting per day. And instances of pecking at each other and the eggs in the nest boxes is down significantly. And when I introduce the new girls to the flock, once they get big enough, there will be more room for ranging.