Yeah they certainly have value like RR pointed out...but after seeing my buddy shoot with one on his .300wby, no way would I want the added noise. I was behind him a good ways and just curious as to how loud it would be, so I didn't plug my ears. My ears rung like I shot a .44 with no muffs....it was horrible. I couldn't imagine shooting that thing a couple times in the woods.
In a hunting situation (for me) I would never wear ear protection, so I personally would rather deal with recoil than noise.