The few times I've dealt with Apple Support was regarding "restoring purchases" not being honored, even though both Me and Apple maintained copies of purchase histories proving the purchases. In summary, Apple Support was top-notch, quick to respond and took care of the situation. Furthermore, Apple threw in a few extra stuff even though the complaints were not against it. Now if you meant tech support, my apologies. I've never had to call Apple in regard to that.
Have to say I one of those people that hate dealing with that, always a battle. But Apple has always been there. No question and stay and followed up afterward. I might be bias but IMO Apple is second to none when it comes to service.
Never an issue. I've had issues with my iPhone 4,5 and recently my 5S, as well as iTunes. Never questioned or doubted the apple support techs. I always buy AppleCare and will continue to do so.