The debate between GPS systems and laser rangefinders hasn't ended, and probably won't for some time. GPS is convenient for a quick glance, and the course mapping is nice, but I always feel a little dissatisfied whenever I use a GPS unit. The touchscreens are generally poor, the distances take a few precious seconds to update (particularly annoying when you're driving in a cart), and you're still at the whim and mercy of whoever mapped the course in the first place (not to mention GPS accuracy, cloud cover, etc.).
The GPS systems in use for golf simply cannot match the accuracy of a laser rangefinder, and I've yet to come across a GPS unit constructed as well as even an entry-level laser rangefinder. (And that's without mentioning smartphone app GPS systems, which I find virtually unusable due to the massive amounts of cellular data and battery they gobble up.)
Oh, and did I mention membership fees? What about battery charging? Or course data syncing?