I had my iBook for 3 years. The only problem I had with it was with the CD drive. The felt sticker on the base of the drive (brushes dust of the disc I guess) started to peel up and put glue on my CDs. It took about a week for it to be repaired - but I think it was something like 4 working days. Fortunately it was still under warranty, so I didn't have to pay a cent at all for the replacement of the drive I just dropped it off, and then picked it up and left when it was ready.

It was really worth it for me. But I couldn't afford the extended warranty on my macbook. Around AU$400 for it - which was more than the RAM upgrade and perhaps the HD upgrade as well...