All helmets are not created equal. That's one thing I've learned in the thousands of miles I've spent on bikes. Weight, vents, shape, and how they adjust are all very important for something that is going to be on your head for hundreds of hours, and potentially save your life. I've found that the Giro Aeon is exceptional. I haven't tried every helmet under the sun, though. In fact, I've been using Giro for the past 4 years exclusively. So how can I label it such?
I wore Giros previous flagship helmet, the Atmos, and found it to be great. It fit well, was comfortable and my head stayed cool. Then, I was able to use the Aeon and my eyes were opened. Comfortably lighter, cool on my head, and the fit had many different adjustment options that have not broken over thousands of miles. It is miles above my already great Atmos.
Giro took something good, and blew it out of the water with something better. The Aeon is everything you could want a helmet to be and more. And it does all that while keeping you protected.