Took me no time at all. I went about 7-8 years without shooting a Glock after getting disgusted with my first one (a 19, wouldn't fire an entire mag without several malfunctions).
Shot a practice match before a Glock match with a friend's 17 and couldn't believe how well I shot it. Getting used to the reset is the key, but I love the trigger, period, along with the grip angle. It's very natural for me.