i'm about to buy a AR15 upper with a permanently attached muzzle brake. i wish it wasn't a perm, but it's too good of a deal to pass up. i don't really give a shit about hiding the flash, i don't do any covert missions, but i do care about sound. i've heard it's a lot louder with a muzzle brake, but what do you guys think? big increase in sound? small increase?