I ride one. For me, I wanted a bike that would be fun for fitness laps around the park, but would also work in Manhattan traffic (complete with lousy pavement). Having not had a bike for years, I did some research, tried out some bikes, and felt most comfortable with the flat-bar road style. It's relatively light and zippy (unlike many hybrids), but with a slightly more upright position and beefier tires than a real road bike. In other words, a really good compromise for my needs at the moment!

See my "I love my bike" thread: http://forums.teamestrogen.com/showthread.php?t=15672