I ran the Southside FA 50K last Sunday. It started in Superior, ran down around Marshall Mesa, down Community Ditch, around Dowdy Draw, up through Goshawk, down to Fowler, up Rattlesnake Gulch, back down toward the Dowdy trail system, up through Mountain Vista and then across 93 to some trails that are south of Marshall (forgot what they're called), to Coalton, and back to Superior.
Honestly, it was great. It was a nice, conversant pace. And on top of it I was able to run with a friend who was running his first 50K! He didn't feel great for the entire distance, but he survived and did well - all things considered. We started a little later than the rest of the group, but were able to catch some slower runners and had a great time meeting up with a bunch of others.
Put it on the calendar for next year. While it doesn't run through the most travelled and/or celebrated sections of Boulder, it does travel to some really great sections that don't get so much attention - Goshawk (one of my favorite areas), Rattlesnake Gulch, and those areas east of the 93. Also, for a FA, it was very well supplied: the aid stations (there were two of them) were completed stocked. I've been to races where the aid was not as good as this FA.
Thanks to CS for putting on one great non-event!