I'm always worried when I see more than 5V/2.4A through a "normal" USB port. This means that they're either supporting Qualcomm's QuickCharge or something Apple-specific, neither of which will necessarily play nicely with "normal" USB devices.

I'm waiting patiently until you start seeing devices like this with a bunch of USB-C ports, where USB-PD (power delivery) can theoretically go up to 100W on a given USB port. If/when such things became common, then you could imagine carrying around laptops without a power brick. That would be really nice.