Only +0 purely because I haven't used argparse myself yet.

Otherwise I would probably be +1, since I have several scripts that have
fairly kludgy hacked together optparse based approaches to handling
positional arguments, subparsers and building new parsers that accept
the superset of options defined in existing parsers. The feature
comparison between argparse and optparse makes it sound like argparse
does a much better job of supporting these use cases.

The reasons I don't use argparse for them are that: a) I didn't know it
existed until recently; and b) the scripts are in an environment where
getting approval to use new third party modules is something of a pain.