the core F# language is great, however, what tends to suffer is the F# specific libraries (you can use all .NET libs, but I'm talking about the F# specific ones

the core F# language is great, however, what tends to suffer is the F# specific libraries (you can use all .NET libs, but I'm talking about the F# specific ones) and community. There are some things that are getting developed, but my experience is that things get abandoned, progress is slow, or things are somewhat clunky. But if you are writing your F# without any need for F# specific libs then it is great and you can interface it with C# code easily.