Oh man, those field sections were the abolute worst! Riding across spongy velcro into a headwind does NOT equal good times!!! That and another looong false flat-to-roller - all in a headwind - had me dying and GRINDING that effing gear for all I was worth. Worse place EVAR to lose contact w/ a group and have to ride solo. That said, the singletrack sections were all a blast this year. Nice and tacky - comedy central at the mud slide as usual.
I've got to say though that 38:16 ended up being a pretty good singlespeed gearing to use for the day. I tried to keep an efficient balance of running/riding hills (the start of the first hill turning right off the rail trail I ran, but as soon as it flattened out a bit I hopped back on and road the slightly less steep 2nd half of the hill).
I think I'd be able to talk myself into racing SS again, especially if I had more base training in my legs (after the 2hr mark I definitely started to fade/cramp) and if the forecast called for less wind.