For better or worse, the "swoopy" helmets are lighter. Designers have removed a lot of material and added the fins/vents they have for a reason-- weight and airflow as other have said. They may look "dorky" off the bike, but when you're riding, a really well-ventilated swoopy helmet feels light and almost disappears. I don't even notice mine anymore, but if I look at it off the bike it looks silly. I used to think a non-swoopy, BMX-style helmet would be better. Now, I love my LAS helmet and would never consider wearing a poorly ventilated hotbox like one of those.