Android and Linux is (shockingly) also automatic. I plugged my phone into my laptop because I didn't want to run down the phone battery while using it as a mobile wifi hotspot. I was shocked to notice that I had Internet access on the laptop before I even enabled the mobile hotspot functionality.

It turns out that when I plugged the phone into the laptop USB, it showed up as a USB ethernet device, which NetworkManager then happily auto-configured.

So clearly 2016 is the year of the Linux laptop.

This has been true for a while now. I remember being equally surprised when this worked on Ubuntu in (I think) 2013.

It's super easy to tether to an iPhone nearby. In fact right now, I click the wifi icon and 'personal hotpot: iphone' appears within .5 seconds.

Instant Hotspot fails more than half the time between my 6s+ and 2013 rMBP (Sierra). And to get the WiFi hotspot to work you have to have the setting app open to the hotspot page.

This may seem stupid, but do you use it when both devices haven't been connected to the internet recently? Seems like it works better if the laptop was recently able to access your iCloud account.

I've not had issues with it using my 6 and 2015 rmbp. It works when my comp is not on wifi and my cell has a cellular connection.