The "we own the hardware and software" is a HUGE HUGE HUGE advantage for Apple. I don't know how you get to the battery life and basic stability levels of a Mac without that integration.
It's a similar situation to Android vs. iPhones in terms of device integration.
Although iPhones don't really get much better battery life than the best Android devices around, if you compare battery life/perf to the battery size, the amount of battery life they extract out of (comparably) small batteries is extraordinary. The biggest/best Samsung phone is 5000mAh, whereas the biggest/best iPhone is 4300mAh.
You just throw away efficiency at a system level when you design a phone based on another company's design (i.e., Qualcomm, usually, for Samsung). Qualcomm doesn't have appropriate incentives to make a device as integrated/efficient as Samsung/Apple do.
