OK, I'll be the odd man out...
I have a reefkeeper lite, and love it. The Apex is great, I've helped a friend set one up, but... that friend _needed_ my help in setting it up. They're somewhat complex, in comparison to the dead simple reefkeeper. Yeah, you can do internet, email alerts, all sort of stuff with the Apex. Stuff... I really don't need.
With the RKL, plug in a laptop with a USB cord to do initial configuration and name your components, use the dead simple menu system to maintain and run the system, easy as can be. No internet needed, no ethernet cable to run, or wireless adapter to buy.
All depends on what you're wanting.
I wanted something to run my heater with a margin of safety, timers for my simple on/off lighting, the ability to keep my skimmer from firing up after a power failure and overflowing the collection cup, and the ability to open my ATO reservoir fill solenoid for 2 hours twice a week. The RKL does what I need it to, simply, and inexpensively.