We at Crowded (https://crowded.co) have had some very good successes with running F# on .NET Core, both with giraffe and just bare ASP.NET Core. The ecosystem has no shortage of good tooling and libraries, all well maintained by knowledgeable authors. Application performance and our development productivity is excellent, osx/linux tooling took a while to mature but is only getting better than ever now.

The choice we made when .NET Core was still in development (pre 1.0) for it to become our main stack is definitely paying off!