I've had Petzl Meteor III for 3 years, now showing several dents on exterior shell, polystyrene interior not cracked! If interior was cracked, would replace without hesitation, since structure and integrity compromised.
My Meteor must be coming up on 10 years this summer (my UKC gallery is so old I can check my helmets' ages there!) and still looks fine. I guess I should retire it though. My first meteor lasted about as long, so I reckon they are as tough as old boots.
