My problem with these things is twofold:
1. I don't think they actually serve any useful purpose.
You should already be wearing a helmet and sunglasses, so why do you need a tight fitting cap with a short/flippable bill? Their wicking properties are practically nonexistant, as are their sunblocking properties. The bill is big enough to get in the way, but not big enough to actually do anything useful. The one possible exception is that I've heard that these things can keep water out of your face if it's raining. I don't believe this, but haven't disproven it either.
2. Douchebags wear cycling caps.
Hipsters. Euro wannabe riders. That bike shop mechanic with hairy legs that swears he rides 500 miles a week on his fixed gear but is at least 20 pounds overweight and obviously painfully slow. People with way too much facial hair. All of these people think it's okay to wear cycling caps, so why would you want to be associated with them? You don't.
I've tried to like them. I've perused the entire catalog over at walzcaps.com, but I really think that they are better left to people you don't want to associate with. And Ivan Basso, who can really do whatever the fuck he wants.