I just started working on this map from the pennsylvania bridge picture on the OP about an hour ago. How am I doing? (sorry for the large iamge)
http://img296.imageshack.us/img296/1820/pennsylvaniabridge0000if1.jpg
I have already optimized, this thing compiles in about 10 seconds, that is, without HDR.
well, its about 2:30 AM where I am, I think I will pick this up tomorrow.
(note: a good part of the hour was spent searching for textures and scaling down the map, as I started off mapping 50% larger than I should have)