Having read all the posts and knowing as much as I know about Apple power supply circuits, I would prefer to build my own power supply.
Apple power circuits are at best on the weak end of the spectrum and apart from being super innovative in proprietary protection are fairly basic and low end. It is all relative nonetheless. If one's benchmark is fake Hong Kong, Taiwan or China power supplies (The likes of Bestec, etc), then Apple power devices are much preferred.
However, neither the efficiency, neither, the stability, nor the reliability of Apple power supplies is anything to look at with admiration. Yes, the cable is designed to melt when short circuited, so is a plain fuse, and more intelligent power supplies have short circuit protection in addition to a fuse as a contingency against a general failure. Even the most basic power supplies have thermal protection, which is present in an Apple adaptor but it is pushed to the limit so that other elements may fail before it is activated.
Apple power adapters and accessories are a case of point in economics, like OEM spare parts on a car. No replaceable 50c fuse is there but replaceable $80 adaptor. Why trigger thermal protection before general failure? Because it is suboptimal economics.
Apple, can use top of the line power supplies with modular cables, however, sales of high margin accessories will decline and about 20% of market cap will be axed.
A user can build their own power supply, which even with the balance of risks is far more attractive.
Think of the intellectual capital that you will build by creating something far more perfect than the fat executive bonus and and outrageous return on capital behind the pretenses of innovative designs. This pragmatism and not ideology.
In fact, one adds a lot more value to the global economy by improving faulty designs (Bill Gates will probably agree) than labor, supplier and service provider arbitrage.
Case in point was Apple's founder and despite his anger at Google, his approach and philosophy was never to take impossibilities for granted.
Unless for some insane reason I opt in to believe the OEM marketing fluff, I am far from convinced that I should not build my own power adaptor to replace the intentionally flawed OEM device! My approach has a lot of risk, but if successful it's return increases with each subsequent Apple device that I own.
Something that Apple can no longer be indifferent to and maybe realize that such a symbiotic outcome may actually be on par with the high margin but subpar accessories sold, and refocus the company on innovation, not rent seeking from tied products!