You'll find all sorts of maps in defrag. Lots of them are "race" style maps, but some are obstacle courses, others are puzzle maps, there's even a few with stories. Lots of people also like to race on the official maps, like on CTF maps showing how fast they can capture a flag given unlimited ammo and time to practice. I even saw a horror map once. They are all anchored by the whole "go fast and get a good time" thing though.

You might also like this video, which is of the map "Final Torture," a compilation map of 5 "torture" maps, where if you fall at any point in the map you have to restart the entire thing. Only two people have ever completed it iirc.