Some of you are underestimating the loss in a 15 second window. Imagine getting the piece you have been farming for in an instance for a few hours/days/weeks and then it drops. You win the roll, and head to the exit. The instance server crashes and if the save was 1 minute or more, you just lost your item. 15 seconds makes that a bit less likely to happen (it will happen to someone, but not as often). I have seen this occur many times in other MMOs, Everquest being the worst. Theirs was a 15 minute timer. If you ever got an item in EQ the best way to assure your inventory was saved was to trade someone a copper piece. Trades forced an instant save. Can't count how many times I've lost drops because of their crappy system and no one around to force a character save.