I've used Giro (atmos) LG (Diamond) and now I have a Laser. I have to say the Laser is my favorite, I am in Central Fl and it vents great- I love the adjustability on the top, so it tightens throughout the helmet and it is really comfy.

I will have to say that I did like the LG more then the Giro and I had multiples of both helmets.

I really think you need to try them on though, because everyone's heads are shaped differently and not every helmet will fit every head correctly.

My SO rides in a Rudy project and he loves his helmet, he doesn't use anything else.