I just purchased a Aquacontroller Jr. I don't know anything about the Reefkeeper device.
I had won a bid, on ebay, for a Octopus 2000 but it was dead on arrival and the seller refunded my money. He said he didn't want the controller back, since it didn't work, but if I wanted to send it out to the company and have it refurbished I could. I got it back and it works like new.
Comparing the two, and mind you the Octopus 2000 has been replaced by the 3000 and now 4000, I like the menu setup on the Octopus. Then again a new Octopus device would set you back about $500.00 versus the $125.00 I paid for the Neptune device. The Neptune device gives you more control over your devices than the Octopus. You can have it turn your hood fans on and off according to the water temp. It can turn lights on and off according to the water temp. It has a moon phase and, if you really want to geek out, it can replicate the photo period according to the time of the year. It has inputs for Temp and PH only; no Orp control (but most folks don't go the Ozone route anyway). I purchased mine with a serial port to connect to a PC (sorry no Mac support, which blows!) It can control X-10 devices or you can connect it straight to one of their power modules (four or eight outlets). It's about the size of a pack of ciggarettes. Comes standard with a dedicated temp probe and you can download a Lite version of their ReefKeeping software from their website.
Hope this helped.
Ordy