I have 2 ReefKeepers. I love them. Great for controlling lights, chillers, fans, etc. You just don't get the pH, and ORP control that you get with the Aquacontrollers. Plus, I hate X-10's...they constantly turn things on and off at non-scheduled times. For the price, the ReefKeeper is one of the best controllers out there IMO.
P.S. I also have a Aquacontroller II, and only use it to control pH, and ORP. I use the ReefKeeper for everything else.