What was tricky about installing the Water Witch?
In my case I made up a small piece of starboard to mount the water witch to, as I did not want to run another screw in to the bilge itself. I then used some 3M to mount that to the side of the bilge where both the switch and the pump were where they needed to be.
The wiring is the same as any other switch, and they give you enough wire to get the connections way high, dry and out of the way.
I have a two tier (actually three) setup in the bilge, and two sump pumps (smaller johnsons) for the showers. Been over a year and not a single pump failure, or switch hang. I test them monthly to make sure.