It is far better than it has any right to be, considering the work they have to do in the background to get it to live happily in NTFS. It still has a way to go, but you can get real work done.

My Linux-of-choice remains Ubuntu on a VM on my Surface, but having the subsystem installed as well is nice. If they keep at it, I can see ditching the VM in a few more revs. X doesn't officially work yet, although you can hack around and get it kinda-sorta going.