Ear Farm, a blog, has done a 4-part retrospective on 8-minute long GNR songs (Locomotive, Estranged, November Rain, and Coma). The write-ups are mildly interesting.
This is the link to the most recent posting:
http://earfarm.blogspot.com/2007/04/8.htmlif you scroll down to the end of the post, there are links to the other 3.