I would disagree about having more value types. JSON has more syntax for value types, but it only has four: string, integer, float, and boolean. XML has less syntax for value types (everything is serialized as a string), but it has a way to define types of attributes with XML Schema and there you get much more primitive types already (decimal, date & time, binary). XML approach is more uniform: it uses schema to look up all the parsing rules. JSON uses syntax for some types and (ad-hoc) schema-like logic for others.