I haven't got the nylon band for my AW, but I've used nylon bands on other watches. I use the Sport band on my AW. So:
Woven nylon straps are comfortable enough and easy to clean (I always rinse mine in the shower after a workout), but they take a little while to air-dry.
The Sport band is also comfortable, and it's very easy to clean and dry. It's easier to put on and take off safely than Apple's woven nylon band, too. It's very nearly my favorite watch strap of any that I own (which also includes bracelets, leather straps, rubber straps, nylon, and velcro).