Seen them survive quite a bit of abuse, including 1 "die hard" style grappling hook when someone fell out of his tree with his sling on.
ROF makes up for the FPS, dont think I would trade that around and see the need to upgrade. I've had 2 Famas's and been around 2 others for along time, I have never seen one go down from internals.
But, I also understand it does happen and that they are hard to replace because of those parts, still the version 1 gearbox remains a favorite to me and I don't see why you would want the G&G to do away with it, their '80 was pretty terrible and I do