I didn't have a lot of info on them to go on when I was shopping around for coops (and already posted a question or two on this forum), so I thought I'd give my experience with EZ Clean Coops, which is the manufacturer I ended up going with to get my "pre-fab coop"!
First of all, I love the design. The EZ brand's key feature are the poop boards below the roosts. Since this is my only experience with chicken coops (this is my first one), I can say that I'm spoiled by this feature. In the future, I will only ever have poop boards under the roosts!!! They are a life-saver. There are zero droppings anywhere in the coop but in the poop boards, and I love it. Clean up is fairly easy, and the droppings go straight into my composter. However, I'd make them out of plastic, not wood, as the wood tends to stain, and is not as easy to clean. I prefer wood because it's better for the environment, but when it comes to chicken droppings (and disease/pest control), plastic is better.
As far as prefab coops go, they're standard. I do love my coop, the nest boxes are the right size, and my girls love it. It's water tight and that's important. I love the three windows so there's good ventilation and my coop never smells. However, if I could do it all over again, I'd probably hire someone to build a coop for me. It would probably be cheaper in the long run, and might hold more birds for the cost of materials. For a pre-fab coop, I'd definitely recommend it though. It was easy to put together, and my husband and I constructed it in about 2 hours total.
On the other hand, for delivery of all pre-fab coops, consider that a tractor trailer will need to reach your house, otherwise you'll be schlepping the pieces of your coop to your house/yard. We have a fairly steep gravel driveway and the Fed Ex guy couldn't drive it up! It was a long day.
Hope this helps any newbies in their search for coops. A prefab coop is a great way to go when you're just starting out. I didn't have the time or carpentry skills to put together a coop of my own design from scratch, so I'm happy with a prefab. I also wanted to focus on the chickens and raise them properly (since this is my first time with chickens), so it worked out well. If you're curious, this is the website for the coops:
www.ezcleancoops.com
Good luck!
THE CHICKEN Coop $300
just a warning. was just trying to find good pre fab companies and saw this thread and one of the links messed up my computer 
