[mrsmrtss]

Well, C# has more powerful pattern matching, only compiler exhaustiveness on types is missing today. In Java, sum types (sealed interfaces/classes) require all members to have the same parent, so they can be used only in very narrow cases.

[vips7L]

As opposed to C# that doesn't have any form of sum types?

[mrsmrtss]

C# will have more advanced sum types this year, it's currently in preview.