[ubuntu] What is the status of hardware support for the Surface Pro 4 and its accessories

Posted this over on the Hardware section but got zero replies. Hopefully this is a better place.

What is the current situation with hardware support for the Surface Pro 4?

Does sleep work? Power management? Wifi?

What about accessories like the type cover keyboard? It's biometric scaer? What about the stylus?

How is touch support for the Surface Pro (or any tablet really) in the latest version of Ubuntu? Good? Acceptable? What specifically doesn't work?

Thanks in advanced.

Side note: it would be helpful if someone with the necessary reputation could add tags for "Surface Pro", "Surface Pro 4", "Type Cover", etc etc