It cracks me up to see people complain about having to "run" in a 5k (because they wanted to walk) or to have to battle the elements. That's why these things say "Rain or Shine" - they really mean it.
My group and I had a blast! The weather was cold, the rain didn't seem to want to stop, but the volunteers and coordinators kept the energy up regardless. There was TONS of color to go around, every station got you doused (if you wanted) and they were more than generous with "extra" color if you asked. At the end the concert and after party were fantastic. The music was great and the energy even better.
After having done several other similar events, I would have to say this was by far the best. Well organized, and fun, what more do you want?