Everyone these days seems to be cheering-on the spread of USB-3 as a universal power and date connector, and especially as a replacement for Lightning and MagSafe connectors. I can understand the convenience of a standard connector, but I would like, if only for the sake of perspective, to put a contrary view!
MagSafe: is a great way of powering a laptop, not only because it protects cable and laptop from physical damage, but it has clear safety benefits: getting your feet entangled with a cable can have very different results according to whether the cable has a MagSafe connector or something more “physical” on the end! I used to run an 11" MacBook Air; I now run a 12" MacBook - the one with MagSafe, and the other without - and I know which I prefer! You know where you are with MagSafe: so long as the connector looks connected then it IS connected!
Lightning: as an incredibly compact connector (making it ideal for applications like mobile phones); it always connects with a positive “click”, and will never accidentally disconnect. For those who appreciate the tactile aspects of connectors and connections, Lightning is second only to MagSafe.
USB-3: Is nicely compact, though larger than Lightning, but (apart from the first few insertions from new) lacks the “click”. Indeed, even new connectors are not immune to slipping out whilst in use: I have lost count of the number of times my MacBook has shut-down because the USB-3 connector that I thought was powering it had slipped out the millimetre or so that will let it lose connection yet still look connected! And, having only the one connector on my MacBook, matters are even worse when I am obliged to use a dongle to connect to combinations of HDMI, USB, wired LAN etc and power.
Of course, a standard connector would be a convenience, but why does “standard” always have to mean “cheapest possible”? For the benefits of MagSafe or Lightning I’d willingly put up with having to carry an extra cable, or an adaptor - but if I must use USB-3, couldn’t they at least have made it with a reliable “click”?