I have had the chance to play with one while i was in the Army, so i know that they are not movie quiet on a 5.56. We did get the chance to play around with a supressed .22 as well, that was loaded with subsonics, and that WAS movie quiet.
I live on 55 acers out in the country and I have set up a range that i can shoot out to 600 yards. I have never tried shooting that far yet, but it is set up so that i could if i want to. My biggest problem is i have one neighbor that is a little old lady, that has a dog that gets very scared of loud nosies. The dog will burry its self under her house, and then not come out for days. When ever I am going to do some shooting( more that 2 or 3 shots) i have to call her so she can drug her dog and lock it up. I would like to be able to avoid all of this, so this is why i have started looking at supressors again. I guess i will have to get one for my 7 rem mag as well.
Thanks for everyones help and advice, i guess i need to get going on the ATF forms.