If you're talking about me I'm just basing my opinion on reports from customers at our shop. They will bring in, say, an iPad 2 with a cracked digitizer. Apple (as in the "genius bar") tells them that it is simply impossible to replace the glass, and the only option is to pay $350 for a replacement (and give theirs to Apple)...we tell them it's $120 to replace the glass. They'll crack the LCD on their MacBook, Apple tells them they have to pay $750 for a replacement...we tell them it's $150 to replace the LCD. If you're under warranty, they're great, but once it's over you're screwed. They also must not have great standards for employees since they hired the douche that ran his own shop into the ground and locked the doors to his shop with several customers' phones still waiting (for weeks) to get fixed.
I wouldn't go as far as to say that AppleCare is *worth* it, it's just that your **** out of luck if you don't get it and your **** breaks.
They still aren't as bad as SONY, who will straight up steal your PS3 from you if you don't pay the diagnostic fee on your console within their short timeframe.