KAOS,
Depending on the type of dropzone that you fly, you will use the GPS accordingly, that means that if you fly on a secluded field with little or no traffic you can use to pinpoint exactly the exit point, but if operate in the other enviroment you can use it to guide you to the jumprun without calculating all the time how to get there the most efficiently way and also with the proper altitude.
One trick that I used when I hauled skydivers is that I got to the runway thresholds (both) and marked the waypoints, then I used the route feature on the handheld with moving map gps, with the "show route" on, it gave me a view of the runaway position when I was airborne; it also help me with the wind correction on the spotting on the jumprun.
BTW I will post a topic calling to see how many skydivers are here on pprune.
