Hi Flow cats are a nice middle ground, you get more rasp, more noise but not too much AND they are legal, which decats are not, although I know if you find an MOT tester who will turn a blind eye you are ok
I got my Berks off a member on here who sold up and took them off his car, the first thing that hit me was the weight of them, I would say that both Berks weight about half what 1 standard cat does
I have CEL light issues at the moment and got some spacers for ZedMan but I am having an upRev soon which will get rid of them anyway