You know what, my Tunze ATO has never failed me... Did have to replace the pump once, but it was under $30. I like the infrared feature with the overfill float switch shut down.

Yeah, it was $200, but no fuss setup and it just works.

+1. I've got two now. Easy peasy. For the one that fills my main tank I've got it modded so that the brain of the tunze turns on an Aqueon Quietflow 8000 in the basement. The tunze stock pump had a hard time with 15 ft of head pressure.

My Tunze only failed me once. Not because of the hardware but because of the user. My output goes into my overflow and one time I was floating a bag back there and it moved the tube so it was pointing outside the tank. Once my ATO kicked on it just shot water in behind my tank until I noticed the water around the tank. Oops!

i just bought the aqua hub ato DIY, it comes with 2 floats switches one for back up, and i must say for 60 bucks it works pretty darn good just throwing it out there

The method of ATO that each of us uses all depends on a persons system, budget, involvement and ability. As stated some peoples tanks are too far away or small enough that its not an inconvenience. Others might not have it in their budget for a fancy controller to handle all elements of their system. Some might find what you just described to be too complicated and risky because they are new to this or don't have the desire to become as informed. And finally, some people just don't understand which end of the hammer to use and need for things to be plug-and-play or as simple as possible.

I started off with just an elevated freshwater holding tank and a float valve and then upgraded to a used Tunze system that I bought for $50. Fast-forward a few years and my current system is a freshwater holding tank that is automatically topped off twice a week from an RO/DI system by a solenoid controlled by my Apex. Two water level sensors are present in the sump for redundancy to stop the Apex from turning on a maxijet pump ever 30 minutes for one minute. When the water level is low enough that the pump does come on it pushes through an inline kalkwasser reactor (I have chronically low pH due to the Ca Reactor). All of this sounds pretty simple to me but when I try to explain it to a random person looking at my tank I can see that its a little over their heads. Literally and figuratively. The 1/4" line from the RO/DI runs across the exposed floor joists in this houses basement. I also employ two water-on-the-floor sensors that will trigger a text message alarm and shut off several pieces of equipment if something goes amiss.