So I showed up and a bunch of snobs gave me a hard time about still having mechanical disc brakes on my bike... Oh wait, wrong thread.
Anyway, it was pretty fun. I sucked, which I expected, and bonked after two laps, which I totally didn't expect. The biggest difference, from a slow beginner's perspective, that I see between CX and STXC is this. In CX, you can generally avoid crashing just by slowing down. In STXC, there were a lot of places where I had to go faster to avoid crashing. I also figured out the trick to doing a controlled slide through gravel by tapping my rear break. That alone was worth the price of admission.
My shoulder muscles and triceps were really sore afterward. I felt like I had just done about 100 push-ups. Can I blame my rigid fork for that? I realize poor conditioning is probably the real culprit, but what I mean is, would that be easier with a suspension fork?