For hands off operation but with somebody there to look at things the controller will be less difficult that alternates.
You will need a way to monitor the amount of CO2 actually IN the water. Bubble counters will show you how much is going into the tank but they will not figure in how much may be gassing off out the top or never really getting mixed into the water. The normal, often used way to see how much CO2 is in the water is a "drop checker". A drop checker changes color from (blue, yellow, and green) as the PH changes. The color judgement of what is which color can be difficult and it reacts very slowly and does not control the amount of gas added.
A PH controller is electronic and gives a reading of PH as well as gives you a way to set the PH and it turns gas on/off as needed.
For my wife, I would need the controller. She could read the numbers and know when they were right and let me know if they were way off. But she would not/ could not begin to judge the color in a drop checker and determine how much more or less gas to add by adjusting the equipment.
Kind of like cruise control for CO2? Not necessary but may save major headaches at some point and will likely stress the wife less. You may get a phone call and have to do some remote troubleshooting but better that than getting home to find the drop checker has been yellow all week but it looked green to her?