Does it really matter at what height the pressure switch is mounted?

I always see it mounted near the bottom of the pressure tank, but I'd
rather have it at eye level.

My setup: a 3-wire submersible pump, a diaphram type pressure tank, a
Franklin pump control box, a SquareD 9013 class pressure switch. The
pump control box is wired between the pump and the presure switch.
The water line is comming in near grade level to the basement and
dropping down to the mechanicals.

Lastly but less important, what is a "pulsation plug"? This is
mentioned as an option on the SquareD pressure switches.

--wahzoo