I think the short delay on the rhythms would just be the same as quad tracking or adding more guitar tracks. whenever something is quad tracked it sounds larger...Unless the your talking about repeating delay?
randy staub
uses a short delay panned opposite to each guitar track in order to give it a fatter and broader feeling
must be going for the Eric Peterson tone.lol.
I use it lightly mixed in on leads (always tempo tracked), dont really use it too much on rhythms unless it is part of the rhythm itself.
This might be of help
http://www.youtube.com/watch?v=nG7GJryimno
randy staub
uses a short delay panned opposite to each guitar track in order to give it a fatter and broader feeling