Last weekend, with no prior knowledge of JavaScript on the server, I created a full NodeJS, Express, Coffeescript, Jade, NPM stack and had it deployed to my linux VPS in less than a morning.
It's my understanding it's not so easy to do that kind of learning and experimentation on Windows.
Although I would recommend going down the MVC route as asp.net forms are sucky. http://www.asp.net/mvc
I know there's an anti-MS tendency round here, but fast experimentation is just as easy with MS these days as it is with everyone else.
The only gripe I've got with MS these days is that they seemed obsessed with videos, which are irritating as you can't go at your own pace (i.e. faster) and it's a nightmare when you just want to find that way of doing x that you remember seeing in the video but not at which point.
I'll have you know that Windows is every bit as easy to experiment and learn on. Microsoft go out of their way to make developer and sysadmin's jobs as easy as possible. New versions of the .net framework can be installed without restarting any services, all previous versions will keep running in parallel, etc. etc. Don't dis it till you've tried it.
It's my understanding it's not so easy to do that kind of learning and experimentation on Windows.