As far as I'm aware, Ada has a much more expressive type system and not by a hair. By miles. Being able to define custom bounds checked ordinals, being able to index arrays with any enumerable type. Defining custom arithmatic operators for types. adding compile and runtime typechecks to types with pre/post conditions, iteration variants, predicates, etc... Discriminant records. Record representation clauses.
As far as I'm aware, Ada has a much more expressive type system and not by a hair. By miles. Being able to define custom bounds checked ordinals, being able to index arrays with any enumerable type. Defining custom arithmatic operators for types. adding compile and runtime typechecks to types with pre/post conditions, iteration variants, predicates, etc... Discriminant records. Record representation clauses.
I'm not sure what disadvantages exist.