I've got the 870 combo with the 28" barrel and the 20" (? might be 18" ) smooth bore barrel with the rifle sights and I've never noticed anything for muzzle flash. It' got a bit of a kick to it but it doesn't really bother me much, mind you I'm 230lbs. Noise wise it's a 12 gauge so wear ear plugs when doing continuous shooting like you normaly would, if your in the bush hunting one or two shots without hearing protection seems to be the norm for anyone. Velocity wise it seems to shoot as well and as far as longer barreled shotguns I've fired slugs from but I really couldn't tell what kind of velocity difference there is between the two barrel lenghts. I have noticed though that the 2 3/4" slugs seem more accurate than the 3" slugs. Hope that helps some