I think the best feature is it's programmable. So it controls your heater, chiller, fan, lights, co2 regulator, calcium reactor, pumps, powerheads, etc.
If the temperature of your tank reaches a certain temperature you can have a fan come on, if it reaches higher you can have a chiller come on. if the chiller should fail for any reason and the temperature keeps rising then it can shut down your lights.
that is just a small portion of what it can do. it can simulate the sun over the tropics adjusting your lighting for different months of the year. it can also do that with the temperature of your tank. it can also simulate moonlight.
it also has data logging so you can track the temperature , pH, etc. of your tank over a period of time.
it just does a ton of stuff that your timers, power strips and wavemakers could never do. so yeah i think either the reefkeeper or the aquacontroller jr. are definitely worth it.