I've been using the Windows Subsystem for Linux (WSL, Aka bash for windows ;) ) since the preview.
When I say using, that's of course a bit misleading. In the beginning it was mostly a new toy to play with since you were quite locked in. The later editions they have made some shims to communicate between the WSL and windows. I'm currently not on a insiders build since this is my work computer, but in the recent versions executing windows apps is as easy as executing linux apps.
It really depends on what you mean by "developer friendly". I'm a developer, although I primarily use the .NET-stack and Visual Studio. I have no problems developing with node, developing web, or really anything. And if I REALLY need something that isn't supported on windows.. Well.. That's where docker comes along :)