I am closing in on somewhere near 4,500 rounds through my little 15-22. My rifle is dedicated just to Steel Challenge match shooting.
Mods / upgrades to my rifle include: HT 24C trigger (great), VQ extractor (essential) and a C-More 8MOA red-dot that replaced my $50 Tru-Glo simply because the CM does not wash out in bright sunlight.
I regularly clean the rifle thoroughly though not after every outing, and recently took out my fire control group so I could get those components really clean.
This little rifle is completely dependable and shoots better that I can operate in a match enviornment. It will eat any ammo I put through it, though my match go-to is either CCI Mini Mags or AR Tactical.
More and more 15-22's are showing up at the club matches I shoot. Guys who thought the 15-22 was an "entry level" gun are putting down their high dollar builds for the little S&W.
All in all I this has to be the absolute best smile per dollar I have ever spent on a firearm; and, as .22 ammo prices have started to come down again the best value to shoot of all the many guns I own.
If you own one you know, if you don't you should get one