Could someone point me to a relatively complete list of new features in each release?
The best list I found was on the wiki:
http://wikihelp.autodesk.com/Revit/enu/2013/Help/00001-Revit_He0/0001-What%e2%80%99s_N1/0002-New_in_...
You can go back to 2012 and 2011 too.
