[Hakeashar]

Yup, it's a bit unfortunate, but that's how it is most of the time.

I found myself using F# for core libraries with clearly defined boundaries between APIs and assemblies - IMO that's where the language shines right now. You can have your core logic contained in a library with a separate, C#-compatible API.

Using F# for WPF, ASP.NET MVC or ASP.NET WebAPI development wasn't quite as stellar experience, also because of the state of the tooling. I'm even wary about type providers, when they work - it's great, when they don't - you're pretty much screwed with no real recourse. In case of relational DB access, most .NET libraries (both full-ORMs and micro-ORMs) are C#-oriented.

Therefore, after including all the annoyances you listed, it's hard to justify anything more than 'handle core libraries in F# with C#-compatible API, do the rest in C# - it's good enough' to the business...