My LBS suggests a Giro Xar and says it provides maximum coverage. It feels comfortable and seems to have really good air flow. I've also seen a lot of people here mention the Bell Super. It seems like a great helmet, but I do have concerns about the venting. I live in Georgia and ride mostly xc, and the heat/ humidity here is brutal. I need a really good helmet, but I also need something with air flow. Which do you think is better?