RTTR's general approach, structure, and features are almost identical to what my reflection libraries look like today. RTTR is thus pretty much what I would use for a new native C++ reflection article series, were I to have the time. It's also quite similar to the reflection/serialization engine we use where I work (which has been used in multiple shipped game titles).
I do believe that there is an even superior approach to reflection in C++ that uses code generation. Such an approach is used by the Unreal engine, for instance, though there are significant improvements that can be made compared to Epic's implementation. A freely available example tool of this nature is clReflect by Don Williamson.
However, as code generation requires additional tools, build system integration, and is difficult to implement independently, I do still feel that pure C++ solutions like RTTR continue to have great value for many projects.