I ran it last year and loved it, best marathon experience ever! Below is my post from Marathonguide.com, you can check out others opinions as well (many have mixed feeling about the race) but everyone is in agreement that it is a beautiful route: http://www.marathonguide.com/races/racedetails.cfm?MIDD=562100411
Expo/Packet-pick up: Great expo - one of the best I’ve seen. As for the packet pick up, please remember to bring your passport with you - US drivers’ license will work (although it took 5 minutes of arguing for me to persuade them to let me register). Also, send in you medical certificate in advance and bring a second version to the registration table.
Day before UNESCO “breakfast run”: At the UNESCO headquarters, they start a 5.2K run on the day before the marathon. A few things to consider before you decide to run it: 1) You must run BEHIND the flag carriers at all times and they are running about 10:30 pace. 2) The “breakfast” is really simply pre-packaged muffins and the like. My experience was that it was fun, but I would not do it again.
Race Day Staging: The Champs was packed - 37,000 registered. Toilets are hard to find and the lines are quite long. Also, don’t even think about starting towards the front if your bib number does not indicate a 3:00, 3:15 or 3:30 marathon. These portions are barricaded and the entrance points are strictly enforced (you will be physically removed).
Race Course: I’d call if “fairly flat,” but it’s no pancake. If you plan to finish in around 3:15, expect to be running shoulder-to-shoulder, with runners 1-meter in front and behind you until about mile 22.
Spectators: Great; I cannot think of one part of the course without spectators.
Race replenishment: OK. No gels, but they had oranges and bottled water. I like the bottled water but I saw a few people get tripped up by the bottles. Watch your step in the aid station zones - it’s very slick.
After-race goodies: Pretty poor - basically, the same stuff at the aid stations with some PowerAde tossed in.
Overall, I highly recommend this marathon!
Dave in VA