Aside from geography ( I can drive to Chicago but have to fly to NYC), Chicago was less complicated. In NYC, I took the bus they provided to the start since we were staying 2 blocks from the pickup. From that point, it was one long line after another. The line for the buses was huge, but moved ok. The line for the security check was really long--that did take me a little while to get through. The wait for the start of the race was long. The weather was nice on the day I did it, but that could potentially be really cold or wet. NYC corral system needs some work. I remember filling out the application with a PREDICTED finish time--that needs to be a PROOF time instead. So many people up there that should not be ( I am competitive, so typically start near the front). Also, at some point the barriers separating the corrals were removed and it became a free for all. I have never had so much pushing, cutting, and shoving before a race. I did love starting to "New York, New York" though. You start over the Verrazano Bridge, which of course means BIG HILL. Add to that the bottlenecking--it was so tight and congested. I never could find a clear path to run. My time for the first mile was over a minute slower than it should have been (and I use that first mile to warm up). It felt congested for at least 8 miles before I could run comfortably. I am no stranger to big races and large crowds, but this was bad. I also don't love the NYC course. Half of it is through Brooklyn--I thought we would never get out of Brooklyn! It isn't pretty either. I loved the Manhattan part and especially Central Park, but by then I was hurting and didn't fully appreciate it. After you finish, it is a LONG walk to get out of the finisher's chute. I did not check a bag--those people had twice as far to go. By not checking a bag, I got a nice fleece lined cape --beat the pants off those mylar sheets you usually get. Some of the bridges on the course are awful. They are very long and the wind never let up.
Chicago was simpler. Roll out of bed and walk to the start. There was a line for security, but moved ok. Full disclosure: I was part of the American Development program for Chicago. I had access to a special tent with the elites (the real elites, as in eventual winners of marathon--I am not elite). We had a warm tent to put our stuff and they had some food/drinks. Staff took care of our stuff and my favorite part was private, clean porta potties. They walked us to the start 15 minutes before the race began--no standing around forever in the cold in the corral. There was a huge fenced yard we could warm up--I was warming up to groups of elite Kenyan and Ethiopian runners. Since I was so far up front, I never had race congestion. The course runs a lot through downtown and is very spectator friendly--my husband saw me several times. The second half runs out of downtown and that was mentally a little more challenging. Chicago is very flat except for a tiny hill at mile 26 (cruel!). It was very easy to connect with my husband later and walk back to the hotel.
I also felt like Chicago as a city was all about the marathon that weekend. NYC is so big--there were times during the weekend that people didn't even know there was a marathon. I love when a city gets behind a race. That is why my heart will always belong to Boston (my fave). Next year is the 40th anniversary of Chicago Marathon. I went ahead and signed up. Chicago timing works out better for me also since it is earlier in the fall.