Go vs C# syntax efficiency

I'm a .NET developer.

I love C#, its syntax and its features, and basically everything about it.

What I dislike about it, is that I can only develop with it for Windows or web (yeah yeah, I know about Mono, about Xamarin and all that, but it's expensive and not out-the-box at all).

Anyway, the Go language looks like a language that's built for compatibility and efficiency, and I decide to learn it.

I'd like to ask to golangers among you who know C#, how would you compare the syntax and the library efficiency of these two languages, or refer me to a post that talks about it.