My admin page has links to Site Map, Groups, Group Types etc., and at the bottom of the page it says "To administer the site-wide services of OpenACS, use /OpenACS Administration/".
From OpenACS Administration there are links to ACS Package Manager and Users, and at the bottom of the page there's a link back to subsite administration, for every mounted subsite.
The confusing part is that admining users is considered a site-wide admin task, and the acs-admin package is not called apm. It's more than just moving a link though, user administration needs to be scoped to the particular subsite.
I'm wondering if the concept of dependant and independant sub-sites is worthwhile. It would be nice to specify that a sub-site of some parent site is visible from can be controlled by the parent site, or that it's completely independant. For example, are users of the sub-site considered users of the parent site, can the parent site admin them? Does the parent site show up in the bread crumb trail of the sub-site? etc...