Like pepsi says , they are very very loud with a decat , never tried mine with the cat so i don't know how much quieter it is . Also don't forget , the 182 system is a straight through centre pipe with no centre box so it's bound to be loud . I suppose you could get a centre box made up if it's too loud .
Personally i can tolerate the noise , just be warned , there isn't a speed when it isn't loud .
From what i've read on here i'd give the blue flame system a wide berth . If the yozza isn't for you consider either a Milltek or Powerflow although having said that , i've also read of some welds cracking on the Millteks .