I've got a Giro Prolight and a Louis Garneau X-Lite, in the past I've used a Met Stradivarius, Specialized 2D and other mid and high end helmets and they're all hot to wear the more you spend you tend to get better padding and slightly more ventilation (which really doesn't make that much difference).
Get the one your more likely to wear, i.e. the most comfortable and which makes you look less like a dick.
I've got a Giro Prolight and a Louis Garneau X-Lite, in the past I've used a Met Stradivarius, Specialized 2D and other mid and high end helmets and they're all hot to wear the more you spend you tend to get better padding and slightly more ventilation (which really doesn't make that much difference).
Get the one your more likely to wear, i.e. the most comfortable and which makes you look less like a dick.