I do believe the RK lite has different options though. If I read it correctly there is one without temp, orp, ph slots to be able to plug probes into. If this is correct, be sure to pick the right one.
I was thinking about the same point on the RK with the things that are available, such as turning fans, chiller,and heater on when the tank reaches or drops to a certain temperature. It will also shut lights off if temp continues to rise above a desired temp. The RK2 gives you a wavemaker and a one touch standby mode to shut off all pumps and powerheads. I think this controller gives the computer geek what he desires in a controller, and it gives the simple minded people like me what we desire. The Reefkeeper is well worth the 300.00 i spent.