I know you have just written the Zed off, but I had a cat back from Charlie 9 months ago and it transformed the sound to a really good sporty performance tone, not too loud, but enough to keep me happy. If you get another one, I'd really recommend it as the early Zed's struggle with producing much noise from the Standard pipes and Charlie is a bargain compared to Scorpion/Cobra budget off the shelf mods.