You get what you pay for....
If all you want to do is see the PH or Temp, buy a probe and stick it in your pocket so you can test every time you pass the tank.
On the other hand, if you want to see your PH every 5 minutes over the last day/week/month, so that you can see the actual effects of feeding, dosing, water changes, etc, then good luck with that hand held probe.
The email/text alerts are invaluable. Temp too hot/cold, Ph out of range, water level low.
You can create your own visual indicators. My lights shut off when the temp gets too high because that is something I will notice when I walk by and not have to read my email/text
Being able to control specific outlets based on the state of a different outlet. I have my Chiller and UV shut off automatically when the Pump is shut off.
I use a separate programmable dosing pump, but shut off power to it if Ph is out of range.
I use the breakout so that I can:
a) monitor water levels with a float switch.
b) wire a switch in to go to feed mode with the push of a button. Circulation pumps, Protien skimmer, etc shut down.
c) wire a switch in to go to specific lighting profile with the push of a button.
d) I wired an alarm sensor to the doors of my cabinet so the light fixture under the tank comes on when I open the door
If you want to simulate nature more closely , you can use the seasonal tables to control sunrise/sunset and moonrise/moonset times through the year.
This really only scratches the surface. I can not imagine having a tank today without a controller. It lets me spend way more of my time enjoying the tank and not working on it.
And I can do everything standing in front of the tank or anywhere on the planet that has internet connectivity via the controllers Web interface or through APEX Fusion.
I highly recommend looking at these programs here, you can get some great ideas
http://www.kenargo.com/apexProgram/