True, but credit cards do give additional rights and protections to the consumer, as well as the various cash back schemes, and so even if one doesn't need the credit, purchasing on a credit card is generally preferable.
While reflection manifests as a surface phenomenon, it is due to the impedance mismatch between the two media and thus determined by the relative refractive index, which is a bulk property. In principle that could be modified by doping and while that can be used to alter color, it is not an inevitable effect.Multi-coatings are almost certainly more effective but, as noted by others, prone to scratching.
I didn't say linearly, although I implied monotonic, which is true, of course. Technology advancement is generally unsteady, so I wouldn't worry to much about the occasional plateau. Additionally, while energy storage may not be improving as fast as we might like, computational power use is declining steadily, so both factors need to be taken into account.
That's a pointless response, not least because it doesn't remotely address my observation. Your snide suggestion to look at the WP entry for physics suggests only that you don't understand physics yourself. If you would like to debate the substance of the issue then feel free to try to explain why I'm wrong.And, as it happens, unlike you I am a physicist, so I don't need a refresher.
The present limitations on battery life are not governed by the laws of physics - simply by the constraints of existing technology on power usage and battery energy density. Neither are anywhere near the fundamental limits imposed by basic physics, and are continuously improving.
Obviously it won't be A-GPS, since that would require cellular radios in the watch. But that's not really relevant to this kind of device since lock time is relatively unimportant for tracking applications provided that it is sub-minute or so.
In the case of iCloud I don't disagree that forcing the sync folder to be on the boot drive seems like an unfortunate restriction, but my comments were more directed at the other poster's various misunderstandings of how a sync folder works and his confusion of the distinction between copy and move.