Compatibility with ubuntu

Ubuntu does have the drivers for WiFi, Bluetooth, touchscreen, detachable keyboard, and the pen - BUT!

I ran Ubuntu 17.10 on a Surface Pro 3 for 24 hours but did not setup a dual boot configuration; I wiped out the tablet and ran Linux on it for the whole day.

You may want to consider using Hyper V, VMWare, or VirtualBox and run it in a virtual machine instead.

Dual booting on a Windows machine does work but sometimes GRUB will get an update and blow both operating systems (you cannot even recover the data)!  Run it at your own risk in that fashion but it should work.

Pen function is not refined and basic, more like a mouse in resolution.  Firefox is sluggish and also Linux is not very good with multitasking but will do it.

WiFi connects instantly but at times, connection will be lost but the icon will display 5 bars.

The keyboard/touchpad work perfect and you can shut off the touchpad via the Settings panel in Ubuntu.

You will get a serious drop in battery life and get around 2.5 to 3.5 hours with the i5 model.

It is said that the current Linux kernel 4.13 and higher includes the Surface drivers (tablets only) but I did try LinuxMint and it did not work.  Fedora does but did not fully test it.