This does work well, but in the current version of PM, the same window also allows you to enter an address, which (in an urban location) makes it even quicker than dragging a considerable distance. I often use an address to get close and then refine by dragging on the map and clicking.
Some confusion is caused by the fact that, in a rare error of menu planning by Camerabits, there are two other places where PM gives access to GPS functions. If you want to use a GPX file, then you have to go into File>Import GPS Coordinates. If you want to view an image's location on the map, the easiest is to right click on the image and select Show Map. Once you realise this, it is very easy.