So I fitted mine today. It's a lot more raspy on my 150 Superlight then the original cat. The cat had a deeper note. Mine seems like it has more torque now although I found my Lambda sensor was loose! The car pops more on general changes and when giving it some, you get some big bangs which is quite satisfying. I think I preferred the sound with the cat on though overall, but the increase in torque is welcome, I've had the back kick out in second a few times uphill which is new. Be interesting to get everyone else impressions. I will get a Dyno on both later this year/ early next year