Who uses it? I haven't until recently and now have tinnitus and whatever the other thing is when you can't make out a single voice in a crowd.
I've just started using clamshells because the range makes it mandatory and then my son gave me these!
Stereophonic and very cool. Read about them here.
http://www.amazon.com/Peltor-Tactica.../dp/B0000X6I5I
These things can actually INCREASE your hearing ability until the hammer falls. I can't wait to try them in the woods, I should be able to hear a deer f**t. That's foot to you youngsters.