I added the emphasis to Pat's caveat. We should point out here that QC in factory ammo occassionally leave something to be desired (witness kabooms in Glock with factory ammo) and other instances of just plain bad lots. Even you buy only quality ammo from a reliable manufacturer, you will occassionally get a bum round which could cause a tap, rack, bang at an inopportune time (like when there's bullets whistling around your head).Based on my experience quality autos are just as reliable as quality revolvers when fed with quality ammo.
The other thing that Pat fails note is magazines tend to cause autloaders more problems than even ammo (but often a tap, rack, bang won't help a magazine problem). I believe even Pat has mentioned one time experiencing some magazine related problems with his Glock 33 and Yukon Delta dust. The sensitivity to magazines can be exacerbated by the sensitivity of the magazines themselves which on day to day routine can be exposed to a lot of rough handling and are generally not as well-protected as our weapons.