"prepared: use extended query protocol with reused prepared statements"I don't think this mouthful is useful in the --help output. The existing wording gets the message across just fine, I think. More details can be put in the reference page.
These suggestions are for the online doc page, and possibly an internal comment in the code.
The pgbench --help just states the 3 possible values and the say which is the default, and indeed cannot say much more.
-- Fabien.
