awesome rifle, very, very accurate 1/2 or better. I shot a mag through my buddies, it's very impressive. I have a jp .223 so I'm biased, but this is my next purchase. Be prepared to wait, took him 7 months.
I'd say it's fine as long as you're not shooting in a covered area. I just use plugs if I'm shooting in the open, double up with muffs if I'm shooting enclosed. It's smooth for sure, though. Feels like a uncomped 223.
It does let the people next to you have it, though. Was shooting out of my brothers Pontiac Aztec during a rainstorm (he's got a tent so the muzzle was outside of the actual vehicle) and there was enough blast to bounce empty brass about a foot in the air. Only touched a couple off before deciding that wasn't such a good idea.