I've had brilliant experiences with Apple support in terms of replaced kit. When the stuff directly effects my ability to earn money every day I really don't mind paying more for access to service.
They replaced my plastic Macbook (remember those?) twice, once out of warranty, due to the case degrading. Replaced my 2011/12 17" unit as the keyboard failed. Caused me a ton of pain as I was away in the US at the time working, to the point that I was going to buy a new one and return under their 14 day thing. They came up with the better idea of just giving me the US 17" unit. Keyboard was a bit different, but it got me out of a hole. Had to pop to a UK store to sign some warranty forms when I got back (dunno what that was about) but like I say, got me out of a hole.
Often the hardest part is getting a time slot for a genius bar! Even living in Central London, where there's tons of stores, getting a formal appointment can be a bit challenging.