FWIW - I just found the note in the "full mirror list" page about not mirroring from the US round-robin which I have taken to heart with an entry in /etc/hosts.
There isn't anything on this page (one might consider an asterisk or permalink to the note since the US mirror cluster appears to be a special case). Nevertheless, sorry for missing that as the round-robin issue is noted.
I think I've managed to get an understanding of the basic mirroring dynamics here:
Nevertheless, it still seems to me that wheezy-updates at an individual member of ftp.us.debian.org
(let's pick on 126.96.36.199) had a 3 minute gap in its Valid-Until (8:58-9:01 UTC on 31 July 2014). Am I incorrect on that point? Is this expected behavior? Might I be better off becoming a push client mirror?
Associate Scientist and Data Center Manager
Center for Gravitation, Cosmology and Astrophysics
University of Wisconsin-Milwaukee