What OS would you want to run on it? I can't think of something better suited. Android apps aren't optimised well for a large tablet and iOS is too focused to work well on a device that is supposed to allow you to replace your laptop. You could run a linux distro but I don't know of many that are touch optimised very well (Ubuntu has something in the works but I read recently it's definitely not ready for primetime yet).
I think Ubuntu touch-based stuff has loooooong been in the works. Unity is a part of it.
I have a touch screen Lenovo laptop I bought my freshman year of college and I put Mint on it. Works pretty well for what I want to do with touch, I can take notes and it supports pressure sensitivity. I haven't had the chance to get my hands on a Pro to test Mint, but that would be my go to.
I used kubuntu. plasma active on a surface 3 is divine.
Maybe I was wrong about Linux then! Are apps optimised in any way? Is this up to devs or does the OS/window manager do any of the work.
I would likely run Ubuntu or LinuxMint. I came really close to buying the system76 Darter Touch when it was available, but the fact that it didn't convert into a tablet was the deal breaker.
Interesting how many responses suggested running Linux. I wouldn't have thought it would even be worth trying on a tablet. First I've seen the system76 Darter Touch. I guess with Unity Ubuntu is quite touch friendly now.