Buy it. Buy it. There is no way I would be without it. Much cheaper than ATT when a replacement issue comes up.
I'm so very careful with my devices, but when it iced over in Houston, I slipped and shattered the glass on my mini. AppleCare replaced it for 49 bucks. It would have been 199 with ATT, or 800 without anything. It is soooo worth it.
I've gone 5 years with multiple devices with no problems till that happened.
The money I have saved over the years by not buying applecare would pay for 2 or 3 idevices, or a new iMac, or a couple of Mac Minis. Never bought Applecare, and never will.
I buy AppleCare for computers/laptops because I plan on keeping them for 3-5 years. I generally sell iPads to upgrade to the newest version so I don't see the point.