Hi! I teach a Visual Design class and have 12 aging (ie 4 year old) iMacs. They still plug along pretty reliably, remarkable considering the pounding they can get. However, Over the last two weeks, I've had 3 power cords die on me. They certainly are replaceable and if you are going to have something on your hardware to go belly up, that's the way to go, but I'm wondering if that is a problem for iMacs this age.