I too wanted a lighter weight helmet and ended up with a Troy Lee Designs SE-3.
I actually found a few different internet companies that offered free returns and ordered a couple different helmets as they all have slightly different fit.
Found the one I like and ended up sending the others back.
With that being said, the SE-3 is awesome and I absolutely love it. It's a blend of carbon fiber, kevlar and fiberglass. The fit is great and I don't get the "headache" at the end of the day anymore. The SE-3 also comes with emergency removal check pads, so in case of a crash your helmet does not have to be removed to have a C-Collar placed on you.
Ventilation is really good as well and with Scott goggles I have not had one fogging issue. I retro fitted a breath box into the helmet without issues and now I can stop and don't have to worry about ripping the goggles off to avoid fogging.
Only suggestion is to really look around and try as many on as possible, most of these high end helmets have a slightly different fit and you can usually find one that really fits and feels I good. Also don't be scared off by price, search the net and check ebay after you find what you want and you can usually find some kind of deal out there.
The TLD / SE-3 also comes with a really nice helmet bag that would probably run 50 ish if you wanted one like it.
Here's a pretty good review of the SE-3 and a video,
http://blog.revzilla.com/2011/02/troy-lee-se3-helmet-review.html
Troy Lee's website,
https://www.troyleedesigns.com/products.php?cat=37
Here's some pics of mine,
