Do you mean the implicit nullable types? Now that you can make nullable explicit instead I really don’t have much issues with it. It is part of the type system, as it should, and you have null coalescing operators. Is it still problematic or are you dealing with older codebases where you cannot set the nullable pragma?

Yes, all that stuff. I try to stick to F# where no special syntax is required for missing values (via Option<T>).