I did the double stack race this year running the 10K race followed by the 5K race. What a fun race even in the rain!! I loved the challenge of doing both races and that it earned you a special medal. The course was well marked and a fast course.
This year they did attempt a wave start for the 5K - this may need a little more fine tuning in the future but things still went smoothly even with how many people were there.
Overall a great race and I look forward to doing it again