I ran the first one, I wasn't fond about paying to run, and paying again to park.
Take a bucket of water, the shower they had didn't do a very good job of getting you clean, especially since you had to stand in mud that the shower created.
Sunday at 11:30 the course will be very nasty. I did the Saturday @ 11 and not only was it a mess, but you have a lot of walkers clogging the course.
I got a big slice in my leg crawling under the barbed wire at the end, the sand had washed away and the rocks underneath opened up my shin.
It was fun, but those were my biggest issues. You'll have a good time, especially if you have a dry person to take photographs.