I rode it last night for the first time as well. Got a quick shower while I was out there. It firmed up the sand and there were a few wee puddles, but it was firm and fast. I was surprised at how much flowy stuff there is out there. By reputation- I was expecting a non-stop gauntlet of hills. A very fun and pretty challenging course.
I did NOT ride the Gosling loop, but got in over 20 miles and 2 laps using this route: http://connect.garmin.com/activity/83999245
Using the map: http://www.michigandnr.com/Publications/PDFS/RecreationCamping/Pinckney_BikingHiking_trails.pdf
I took shortcuts from 5 to 4 and 11 to 10 on the first lap. Second lap, ran 7, 5, 6, 4, 3, 8, 9, 2. Requires very little doubling.
Don't follow that actual track for navigation. I re-ran a few sections and went the wrong way from 9 to 8 once.