Yeah sorry I didn't mean to make it seem like it's a cluster of idiots vs fast paced dicks. It's an awesome event, and this will be my 3rd as well. I love it, it's a great time with so many awesome people.
I was being pretty general, but yeah the above folks are right - while you'll almost always be around a group of people you do have to be careful because there do tend to be clumps of riders that are mostly unorganized - and a great point about the hills too.

Just practice common sense safety and pay attention. If you're an experienced cyclist you know how to ride and what to look for others doing. There no doubt will be crashes - there always are. I'd say over half the time it's more inexperienced people that are riding in those large clusters that end up clipping someone and down they all go.