i got apple care once on my 2012 rMBP. I was worried that apple had pushed the technology too hard for the hardware and I could be saddled with issues down the road between the fans, battery, and gpu.
the gist is, I'll never buy applecare again. It's just unecessary unless you have the $$s to throw around.
applecare+ and applecare are very different things. accidental damage is all it is about