I must disagree my second hand shurflo has yet to burn out any contactors in 18 months.
I sometimes turn the flow down a bit with my tap and I can hear the pump turning on and off.
The original Shurflo pumps we had were 65psi rather than 100psi. Cycling would be greater on these units than on the current 100psi pumps.
Although I recommended a relay if this is how you operate, I personally would never not have a controller again. I love a fast flow for rinsing, but I find I waste water with too higher a flow rate with the washing and scrubbing phase even using the controller.
Tbh honest water usage isn't an issue for me if it was I would use a controller.
I've never managed to empty my 400L tank yet on a full day.
Things have moved on since we went to controllers.
We used 1/2" garden hose (smaller bore diamt hose (minibore and microbore) wasn't readily available and Williamson's wouldn't guarantee the Shurflo pump if you used it).The jets in the Vikan brushes were 3mm in those days as they were hose joiners. A Shurflo pump could empty a tank quickly. I used to get through 475 litres before mid afternoon. When I fitted the controller I used less water (375 litres was the tank on the trailer) and very really used the additional 4 drums of water I carried in the van. I worked an extra couple of hours and earnt more fitting the controller as I wasn't wasting as much water.
As I didn't have an IBC tank then, I was processing water directly into the trailer tanks overnight. When the water was finished during the day, that was it.