[antlr-interest] Which to use StringTempates version 3 or 4?

[The Researcher]

I have the lexing, parsing and tree rewriting completed and will now be
doing a proof of concept for the next phase to see if StringTemplates will
work as expected. This will be my first use of StringTemplates. Since ST4 is
so new and is not documented in the books, should I start with ST3 or jump
into ST4?

Thanks, Eric