So being that I'm less than a year into my handgun addiction (thanks Glock) can anyone tell me if the recoil buffer is something of any use? Saw the part on amazon and it says it's made by Glock, I guess a factory part? Also wanted to upgrade the recoil shaft to a steel or tungsten and what advantage if any to a heavier spring. I understand the factory is 18lbs. Any insight or links to this would be appreciated and thanks!