I've got a G20 that is about 13 years old. The recoil spring is weak enough that if I jerk my hand backwards or forwards quick enough, the slide will move out of battery a bit, and "clank" back home. I figure it may be a good idea to have the whole pistol gone through, rather than just throwing a new recoil spring in there. I've been told that if I send it to Glock in GA, they will go through the whole thing, replacing whatever needs replacing to bring her back to new specs, as well as adding any updated parts, for very small cost. I was just curious to hear from some who have had them do this, as far as how long they had the pistol, how much it cost, what they did, etc. Also, typically how much an FFL holder/store would charge to ship it out and receive it for me when it's done?