I log my rounds sent downrange each and everytime I go to the range or a training class so I know exactly how many have gone through my guns.
I'm guessing protracted firing with a worn recoil spring is going to incur more wear the gun than regular replacement for a new unit.
Additionally, since my SR9 also serves as my house/SD gun, I find running it until it stops running to be less than appealing, especially if it stops running when I need it most. Just a little preventative maintenance to replace a spring/guide rod or other components like magazines - which get dropped on gravel, sand, mud and concrete during classes.
If I had the time and money, I would love to be able to put 500 to 1,000 rounds downrange a week but alas, I don't have enough of either to facilitate that. Only 3,140 through the SR9 since purchased last Sept.