Originally Posted by
WineCountryUA
At the top of this thread is the thread's wiki, where many of these benefits (published and unpublished) are listed. it is a rather long list, so easier to refer to the wiki.
The list is a good overview/outline. On top, "going the extra mile" by individual agents (phone, airport, CS, MP desk) in particular situations can result in outstanding treatments, which constitute additional benefits (annecdotal/unpublished).