I have a Chuxaway that we installed about 18 months ago. It has worked flawlessly and I'm very happy with it. I chose it because I wanted one that worked on batteries and I liked that the controller doesn't have to be right by the door. It works on 3 AAA batteries. I changed the batteries at the beginning of each winter so I wouldn't have to go out and change them in the rain and cold. They were still working fine each time I changed them. I have my controller outside of the coop and run, so if I want to manually open or close the door, I don't have to go into the run. I also didn't want one that worked on a light sensor because I have motion detector lights in my yard and I certainly didn't want the door opening at night when there was movement around the coop that turned the lights on! When I bought my door opener, it had to be shipped from England, so that was a disadvantage, although shipping was pretty quick and I had great communication with the company through email. It seems to be a small family run business.
http://www.chuxaway.com/