I would say that if the dispatchers use GPS to know where the techs are without calling and asking, but never are allowed to harass the tech about what they are doing in a particular spot for a particular amount of time (if it's that important, call the tech in and let the Service mangler ask him behind closed doors.
I have gone from no GPS to a company that has all techs on GPS for years. it makes my life better to not have to update the dispatcher as to where I am and where I am going every time I move the van. the management has gotten over the idea of bugging every tech every time they stop at a grocery store or bank on the way home.