AppleCare extends the original coverage from one year to three years - total - from original purchase date of the Mac - and not the purchase date for the Applecare coverage.
You have to add AppleCare before the original 1 year expires. Total covered time will still be 3 years
Any covered repair is at no charge to the customer.
Coverage extends to factory defects and failures, but will not cover damage or abuse.
If repairs are needed, time can depend on the local store. Some repair issues might take extra time because of the need to replace multiple parts. Hard to say when you don't know the circumstances. Could be an extended time, or could be while you wait, or even while you watch.
Very good and comprehensive answer.
For a computer (or iPad) I always buy Applecare. These days, I buy it when I buy the computer - it is one less thing to have to remember to do when I am next home, as I can be abroad for months at a time.
However, when I bought my first Apple computer, in 2008, I didn't have funds immediately to buy Applecare; nearly five months after buying the computer, I was sent abroad, expecting to be away for four months. In fact, I was away for six, and bought Applecare on my first leave home.
Applecare covers three years from the day you buy the computer, and it can be bought at any time during the first year of ownership of the computer.
Personally, I always buy it, mainly for the peace of mind it gives me for three years. That means that Applecare is the 'cycle' that determines when I upgrade a computer, not technological advances.
While Applecare will not add hugely to any sum of of money you might earn from selling the computer, I suspect that it might make the sale itself a lot easier, as it will also give potential buyers peace of mind.
I have actually used Applecare, and I have found that - to a large extent - it has paid for itself.
My original MBP suffered a HDD failure when it was not about two and a half years old, and that was repaired without a problem by Apple under Applecare. Two MBAs (my previous 13" and an 11") suffered from Magsafe problems, which were also dealt with by Applecare. More recently, two different MBAs (my current 13" and my previous 13") also had keyboard problems - two particular keys failed to work on one, and the touchpad gave problems on the other. Again, Applecare to the rescue; in one case, the entire keyboard was replaced, and the touchpad was repaired/replaced - but worked perfectly well afterwards.
