Last weekend I completed the Honolulu marathon! I did not run the race as fast as I had wanted to but it was a good experience. It took me ~5.75 hrs. I was hoping to at least run it under 5 hrs but the torrential downpours that we had during the race (one of them ~20 min into the race) really slowed me down. My feet were pretty raw running in soaking wet socks and shoes. I had to walk a significant portion of the marathon because my feet were blistered and killing me.
One of the other things that slowed me down was the terrible design/layout of the course. At one point the course was 6 lanes wide and then it quickly narrowed to 3 lanes and then it narrowed to 1 lane on an uphill. The pace during that one mile was about 4 mph and there was no way to get around the huge mass of people. There were quite a few areas where the course was too narrow for the 27+ thousand people in the race.
I did have some fuel in the tank when I reached the finish line. After walking a few miles, I ran the last mile at about an 8 or 9 min/mile pace. My feet were on fire by the time I reached the finish line.
All-in-all it was a very good experience but I am not sure if it is one that I will ever repeat.