The coop we built from some diagrams in an old organic gardening magazine served it's purpose well, but had some drawbacks. It was very heavy and difficult to move, quite hard to clean, and hard to completely secure. The final straw was when we found a mouse or rat was trying to take up residence in the next boxes.
For the new coop, we settled on a Chick-N-Hutch with an attachable Chick-N-Rabbit Pen. It was easy to put together, is relatively light, and was cheaper than the materials we spent on the original coop. It has a pan under the wire mesh floor that collects the poop and can easily be slid out.
The only major downside so far was that it had an unsecured swinging panel on the back wall that we thought a raccoon could exploit. I replaced it with a thicker hinged door with a latch.
Soon after we set up the coop, Madeleine learned that if she got scared of the chickens (pecking or chasing her, which they occassionally do) she could run inside the coop and close the door behind her.