My wife and I raced in the 2012 Fiasco, and we'll be back; great race! You probably won't set any personal records on the XC course due to several short, steep hills, but your knees will thank you. The surface is mostly mulch/dirt, so it's very joint-friendly (hey - it matters once you're in your 40s!). Loved the bike course; very flat, save for a steady grade (~1 mile long) at the start that you'll repeat just before you finish. I averaged 22 mph on my TT bike.
Definitely a big thumbs-up for the run and bike course, and for the volunteers helping at the event and out on the bike course! Like a well-oiled machine, those folks in the Tri-Cities know what they're doing.