I had a great experience this year with the Shamrock Shuffle. The race is extremely organized and very well run especially considering there are 30,000+ runners. The slight annoyance is that runners need to be at their specific coral 10 minutes or so prior to their start time (which everyone doesn't always realize). The timing at least keeps the race moving along. I felt the earlier corals weren't as crowded as some of the later one might have been. I didn't have an issue with avoiding runners during the course. Overall I had a great experience and look forward to running it again next year.