I've had a couple, as it is the cheapest 9mm I'd buy and rely on. I've never had a real problem.
The sight was not centered on the 2nd one, and I didn't notice it when I bought it.
I took out the set screw, and tried using a brass punch... I actually bent the bunch - it wouldn't budge. A hairdryer didn't help (for the locktight) either...
So, I called Ruger. They were super friendly and emailed me a return label in 2 min. They paid shipping both ways for the entire gun, and I got it back within 3 weeks.
Honestly, the best customer service I have had yet from any gun company I have ever dealt with.
Now, the gun is far from my fav, and I find that the trigger is not that great. But the gun works, and its not a bad gun.