Going in Saturday for my "4th" (actually 2nd since I drive 25K/yr) annual service. The service advisor told me "the 4th annual is very large as it's right before you go out of warranty and we want to check everything over just to be safe." Not that I don't trust them, but it seems prudent for me to check what I can prior in order to minimize the chance of something being missed. My 70D has had virtually no problems since new so I'm hoping that doesn't change when the odometer hits 50K.... I'm not planning on purchasing the ESA.