My experiences (PLURAL0 have been very good
I have had a number of warranty repairs done on the Apples I have responsibility for. This is from a University so there are a couple hundred Apples in my area and occasionally, like anything mechanical or electronic, a problem will occur.
Because of service contracts, I have had to deal with a couple different Apple warranty service providers. Both have been very good. There was one system, a G4 that was almost out of the third year of Apple Care with only a few months left. It developed an intermittent freezing problem. After a couple of trips to the warranty repair center, Apple just replaced the system with the current new model on the shelves at that time.
The other times I have had warranty service, it was done in just a couple of days. In fact, once a system had some really vital info that was needed immediately on it and the service provider got the thing repaired and returned to us just the second day following when it was delivered to him. That time included the time needed for a part to be shipped to him.
Overall I would grade me experiences with Apple warranty service as an A|