GTK+中基于模板的UI的优点是什么

Is there an advantage of using a "Template" based method in GTK+ apps? I am making my first GTK+ app, and I am finding on the internet that there are many variations of creating a GTK+ apps, some older looking methods, some newer, I looked at the GTK+ dev guide and it uses a complex looking "Template" with sub-classing etc. See: Is there an advantage of using a "Template" bas