Would be great if Strava could categorize courses, or offer some kind of difficulty score.  (GAP doesn't do it).  When watching the Tour de France, they have categories for the hills.  Would be great if you could categorize individual hills during a run, but better yet to categorize the entire course.  Boston may be net downhill, but it's a lot tougher than running a flat course.  Courses that have hills at the end would be more difficult than the hill at the beginning.  There's a lot that goes into that determination, just hoping someone can come up with a good formula.

I just think it would be a very interesting conversation piece for people to be able to talk about the difficulty level of the courses they've ran.