This post prompted me to do some field research. I checked my G26, where is the damn thing? Oh, yeah in my waist band (have I mentioned how much I love my Galco)?

Anyway, while it does protrude slightly, a knife's blade or maybe a small screw driver's worth, it is not as pronounced as BM's SS guide rod and nowhere near as much as the one shown by billt. Not perfectly flush, but close. My G19, easily located in the night stand, is perfectly flush, in fact recessed, but its a gen 1 gun, a different animal.
FQ13