A couple of linked articles with a strong story on the benefits of choosing F# over C# for reducing the bug count and reducing the size of the codebase.
Simon Tyler Cousins compares two similar projects with F# clearly superior to C# in every category for those projects.
Don Syme opines that a key benefit of F# is that nulls are all but eliminated in the code and references the manifesto for Not Only O-O:
We are uncovering better ways of developing software by doing it and helping others do it. Through this work we have come to value:
Functions and Types over classes
Purity over mutability
Composition over inheritance
Higher-order functions over method dispatch
Options over nullsThat is, while there is value in the items on the right (except for nulls), we value the items on the left more.