I just read this mini-essay here:
http://en.wikipedia.org/w/index.php?title=Wikipedia_talk:WikiProject_Chemist...
It is about the effect on the parser of large navboxes (and of other templates). It is a bit technical, but I thought it might be of interest.
And I don't know how I ever missed this:
http://en.wikipedia.org/wiki/Wikipedia:Overlink_crisis
It really is worth reading all that essay and its talk page.
Carcharoth