Too little shade along many stretches of road. Now, sun/heat is not a problem in Vermont, but last two years where very warm. '16 was canceled at noon; '17 the start was moved an hour earlier in the day
The "Assault on Battery" is the only real climb and comes at 15.5 miles. It's long and steep at the end. I power-walked it, and I do not think I lost that much time -- but sure saved some strength!
It's hard to get downtown and parking is a bear. Give yourself plenty of time and anticipate a bit of a hassle getting back out of the crowd unless you're finishing sub-2:45.
By AO about 2016
My First marathon, I loved the city, and the support. I loved the varied terrain of the course, from city streets, to rolling hills, to the burbs with their parties. I hated the heat, I hated blowing up, and I hated not getting an official time due to course closure. I don't think the organizers could have done anything differently, it was just a terrible day to run a marathon. The weather did not cooperate.
Be prepared to be exposed. There isn't a ton of shade on course, wear sunscreen, and be aware of the crazy New England weather which sees 40-80* days.
Don't worry about down town parking, there is plenty to be had, just get there early to avoid road closures. The design of the course doubles back and around, so there are opportunities to see the race multiple times from the same location. Also, be aware there are a ton of non marathoners, which make the course filled with a variety of expierence / and fatigue level folks, not just folks at your pace, which can alter your perception of the course. Nothing worse than someone 2 miles in when you are 18 deep and feeling the wall.
By JP about 2012
Very scenic, enthusiastic crowd, beautiful town, good volunteer support. The only downside is the emphasis on relay racing. Tough to have droves of fresh runners bounding by you 20+ miles into your race.
Rather twisty the first 2-3 miles. Stay away from relay exchange zones. Biggest hill about 14-15 miles in.