I bought this for my wife and she wore it on our most recent canyoneering trip. It kept her cool, wicked well, and looked great IMO. It held up to the pack and squeezing through slots like a champ. It's a winner.
Gotta protect that brain. Plenty of ventilation, and the helmet fits well. I always had those solid helmets before this, but I have certainly noticed the better breathing of this helmet. I have been very happy with this. Hopefully I wont have to know if protects well.