I was trying to use these switches with the Pside-Kick complete pump control package. So we tested the heck out of a few of them. They have a delay on pump start and pump stop so when used with a small tank, you run out of water for a second on pump start and the pressure spikes on pump stop. They also glitched, showed an error, and shut the pump down occasionally for no reason. It is a good idea, just not a good switch.
Amtrol made these so they could narrow the on/off bandwidth to 10 PSI. That way you have to buy twice as big a tank. They like to sell tanks so go figure. With two huge tanks the delay isn't noticed very much.
Have also talked to several other installers that are not having any luck keeping them working. As you can see on the Pside-Kick, I am staying with the old faithful Square D.