My hens seem to prefer individual nest boxes, but to be honest... I never really tried the community type. I use milk crates laid on their sides on top of a wooden shelf we built in the coop. I also added a small strip of cage wire to make a lip along the bottom of the box, to help keep the hay in the nest and to make it harder to accidentally (or purposefully) roll an egg out of the nest.
The advantage to using the separate milk crates is that I can simply move them around when needed. In fact, I have a broody hen in one right now; and I was able to lift the whole nest and move it into a broody pen we built under the shelf, to separate her (and her future chicks) from the rest of the flock. She even stayed in the crate while it was being lifted and repositioned, with no problems whatsoever.
I have noticed that the hens will all use the same nest box to lay their eggs whenever possible, regardless of how many are available.