Lightweight and comfortable
I had been wearing a Giro helmet for a number of years (probably too long 5+ yrs) so I definitely needed a new one. Realcyclist put the Louis Garneau Diamond on sale and I decided to get it. I have not been disappointed: It fits my head perfectly with the Spiderlock retention system (ie. fits true to size according to head measurements), it is comfortable on long rides of 4+ hours and easily provides as much ventilation as my previous Giro helmet. It also appears to be constructed well to protect your head. Bottom line: it does its job well.