I rode Pat's fixed gear to work yesterday. The hills weren't that bad. In fact I climbed them faster than normal. Going down them was a greater challenge. I couldn't fly like I normally do. And there's reaching that cadence of 150-180 that feels like 600. Slowing myself using my legs was rough on my knees. There's probably a technique to it that I'm not aware of. Regardless, I was very thankful I had a handbrake. The main thing I noticed was that the bike forced me to focus more on my body, letting my legs do the work and keeping my upper body relaxed. It's kind of like hockey where you skate from the hips down and puck handle from the waist up. When my mind wandered I found myself bouncing on the saddle and my shoulders would be tensed up. So that was emphasized more so than my road bike which allows me to coast. Also, I found I needed to be prepared to stop. You don't--at least I don't--have that short response time that a regular bike allows you to stop or accelerate. Track standing is still out, but I can go really really really slow. The bike increased my commute time by about five minutes, but since I treat my commute as a twice daily workout I had no problem with that. The only thing I would change on the bike is either adding an adjustable stem so I could move the handlebars up and back or replacing the bar with one that allows me to sit up more. Overall, it's a fun bike.