I've always said if it ain't broke don't fix it. my RIA 45acp ran fine right out of the box. I keep it clean and lube the slide rail with a high tec lube from Brownells.I'm really happy with my RIA 9nn but it waa a bit of work to get there. A lot of the final fit is done by hand and has varied widely in the three RIA 1911's I have. My 9mm was in the middle of the road and of the box it could not get through 10 rounds without a hiccup.
"The Colt .45 automatic: A shop manual" by Jerry Kuhnhausen is a great reference, and following his inspection procedures for a new gun is perfect. I wound up following these procedures and the Rock has been 100% reliable since then. Mostly focusing on burrs, tool marks, and high spots on barrel to frame fit. Both the barrel and frame had high rough spots that needed to get knocked down with a stone:
I also hit high spots on the inside of the dustcover, the breach face, and the slide stop to reduce friction and wear. All that made the action buttery smooth. While I was in there, I polished the trigger bow & channels, put in a reduced power recoil spring and increased power hammer spring.
That made it run like a champ! I latwr added better sights, tac hammer & grip safety and it is now my go to 9mm for fun/recreation. Here it is after ~3,000 rounds.