The Chicago marathon is an amazing marathon and I was super happy to have run it. Getting to the expo and race were extremely easy. I took the Green Line down and was basically at the start line in an hour. This was in stark contrast to the NYC marathon, which took me about 3 hours to get to the start line. I got to the start about an hour before my start time and had plenty of time getting through security and gear check. Do note that getting through security did take some time. There are a lot of single file lines so if you're running late to your corral, this might be a problem.
The race is amazing. There are a lot of neighborhoods to get through in Chicago and you will never feel alone in this race. There is a LOT of crowd support on this race, so much so that there is a bit of a crowding problem along the route. People want to see their runner and will often narrow the route making it difficult for runners to get through. There are also a ton of water stations. I never felt dehydrated during the course. The first half of the course is completely shaded by skyscrapers making the initial part of the race very pleasant to run through. The second half is not shaded at all so be aware of your hydration. Luckily, the course support had sponges soaked with water and plenty of people spraying runners with water. Hooray! They also had big screens at mile 13 and 26 where people who send cheers to their runner. Unfortunately, their timing system was a little off and so I didn't see any messages for me as I ran past, but I did get the messages in an email after the race was over. :)
When I told everyone I'd be running this race as my second marathon and that my first marathon was in NYC, they told me that'd it be easy because the Chicago marathon was as flat as a pancake. Well, they were correct for the most part. No one told me that the last 0.2 miles of the race has a bit of an incline. I honestly should have looked at the elevation map. I turned the corner and was devastated to find that hill. LOL. I still pushed through and beat my PR by 25 minutes so that's a win in my book. :)