Thanks!! I will look into it.
Almost every high end reef you will see these days has one. It provides redundancy and monitoring of tons of aspects. If anyone mentions reef-pi to compare it- know that the reef-pi is a in-progress DIY controller that does a small portion of these things. It will also cost hundreds and hundreds of dollars to get anything close to these features, and have a mediocre (but in development) interface.
Some things I have mine do, ill list the "stock" things I use on the apex 2016.
Notification/warning:
Notify me if my skimmer is full.
Notify me if my ATO reservoir is empty
Notify me if my sump water level is low
Notify me if my sump water level is high
Notify me if leaks are detected anywhere.
Notify me if my temperature is out of range
Notify me if my pH is out of range
Notify me if my salinity is out of range
Notify me if any of my devices are using too much or too little power (A fault).
Take action:
Shut power to the heater if the heaters internal temperature controller fails.
Common cause of tank crash,.
Turn off my skimmer if the cup is full.
Shut off all non-essential devices if the power is out (I have it on battery backup too run just a wave maker).
When I press one button, all pumps shut off so I can do a water change without fiddling with plugs.
When I press a feed button, the return pump and skimmer shut off for 15 minutes before resuming.
Used as a timer:
Controls the time that my 6 t5 bulbs are on
Controls the time that my 2 t5 bulbs are on
Controls the time that my refugium light is on
Controls the program of my LEDs
Controls the program of my skimmer-cleaner; every 6 hours.
Thats just some of the features I use on the standard 2016 unit. I also have their doser for my 2 part

. (Though currently off)