I just got back from my first long ride. Went a bit longer than I planned because I blew past the "town" (looked like a few farm houses to me) that I was going to grab dinner in and turn around. All told I biked about 40 miles (15 in the city, 25 on the crushed limestone Mopac Trail). It took me about 4 hours total (including about 20 minutes of rest time stopped at various points). Discovered my rear wheel was not trued and was scraping the brake the whole time. All in all, though, it went well. My bike shorts irritated me at times on one side (Pearl Izumi Attack Shorts), probably because they kept riding down a bit and then bunching up. The saddle was generally pretty comfortable, especially compared to my old bike, but could be better. Had to stretch quite a bit when I stumbled back into the apartment to avoid cramping, but that feeling has gone away. Now I'm just really tired.
The good thing? If I can do 40 miles relatively easily, I'm definitely hitting the 47 mile loop of the Heatstroke 100 if I can't do more!