I have worn the same David Clarke H10.40 for the last 20 odd years instructing in GA aircraft. Has cracked in the usual place and gone through 3-4 gel earsets which only seem to last a few years.
As for hearing damage i am now starting to get a ringing in my left ear, which i notice when lying in bed.
Short term i think they protect your hearing, but long term i suspect the noise just penatrates your skull and does the damage from the inside.
Also the constant racket on the radio.
Other than wearing a bone dome i can't see how hearing damage can be avoided...other than giving up flying noisey aircraft.