So, the nickel version:
In finished in under 5 hours (4:58!)
I ran the whole way.
I was not last.
I sprinted the last 100 yards, which made me almost barf.
I did not barf.
My muscles are starting to feel better. It's my sunburned face that is the problem.
Will I ever do this again? I hope not. However, I have a funny feeling that, once recovered, I could forget the pain, rather like childbirth, and foolishly sign up for another one.