F# supports both functional and OO call styles. That's why you have both `|> List.map` and `.Select`. It can be a bit confusing at first, but the interoperability with C# is worth it.

Array lookup in modern F# is just `foo[0]`.

Subtyping is much less common in F# than in C#, so the need for covariance/contravariance is correspondingly lower. Personally, I've never needed it.

F# support in Visual Studio is now excellent. You can also develop F# in VS Code.