We are Merrill distributors and have been using their switches for 4 - 5 years. No problems here.
We used to build a switch very similar to this back when we were selling a three wire 3" submersible pump. They came with that rinky dink Italian control box that you had to have a pocket screw driver to access the wire screws. So we bought a bunch of run caps from Pakistan (they looked just like Merrill's) and we epoxied them to the top of a standard pressure switch. Drilled two holes for the wires to go through. We even drew up a diagram had a bunch of them run off so we could stick them inside the cover to show how it was wired. We could be using these today, and don't know why we aren't.
In case you guys didn't know. You can replace a standard 1/2 thru 1.5 hp control box with a 10 mfd run cap. It's wired in between the red and black wire. It will start the motor and cheat the meter while the pump is running. We do it all time with Franklins boxes. We rebuild them with the run cap and sell them to customers. It eliminates the Start cap and the Relay. Dab sends their control boxes out the same way.