Am thinking of picking up a new guide rod assembly for my G17. Probably will go with a Tungsten, to help with the recoil and muzzle flip. I have the factory plastic in it now. I'm debating on the spring poundage. Factory weight is the 17 pound spring, but I'm debating on that or the 20 pound spring. It's only three pound difference, but I'm not sure which would be better for me. Any input from forum members? Also, has anyone ordered from Glock Store and what are your experiences?