I've done this a couple of times and it is fun. Dark clothes worked best for me the mud really stained the white top I wore the first time. There is a loooong up hill and then a long down hill, not a lot of flat but in saying that I ran it both times and it wasn't that hard cause it is almost all dirt roads. Alot of people throw their shoes away at the end I did once but once I just rinsed them clean and left them out to dry and they were fine. When you climb over the walls turn around and lower yourself back down or you could face plant into the mud (not that fun, trust me on this). There are group showers outside and only cold water.
I am thinking about doing this in October too if I can talk my DH into it.
Have fun.
Jones