Having just installed the full leoVince (From Biohazard )I thought I'd tell you what I know..
First, the complete system has 2 tips, a 32mm and a 40mm, and also comes with a dB killer disc that you can drop in to shut the whole system down if noise is a problem. I have tries it with the 32mm tip, with and without the dB killer and can tell you it rocks
With the dB killer in it has a little more torque down low up till about 6500 where it goes fairly flat. It performs about the same as the stock pipe?, or maybe just a little more restricted in the higher RPM. But good for around town and the noise is a little more than stock at idle, much the same at higher rpm, but still very quiet.
Without the dB killer it is great. Good torque down low, similar to stock, but at about 6500 it starts to go and will pull hard to about 9500rpm and only slow a little as it easily hits the rev limiter. It is a lot faster than the stock pipe. I do find it loud on the bike, but people tell me that off the bike when going by it's fine, not to load at all. I think there is some sound reflection coming off the tail unit & number plate that makes it appear louder than it is. I think a tail tidy will stop that & that's next on my list.
Just a little warning that at first the bike was very flat in the low and midrange when the muffler was first installed, but after a couple of days it came right as the ecu adapted to suit. Now it's all good. All I did was disconnect the battery whilst I changed the systems over.
I think the 40mm tip would be a track day thing.
Hope that helps.
For Leo Vince, I think the LV ONE EVO is quieter than the Corsa.
I ordered an Arrow exhaust for my bike. Website says it produces about the same dB's as the stock muffler and complies with EU noise regulations. I should be getting it in the next day or two and hopefully will have it installed soon. I will provide a review once installed in my separate "Arrow Exhaust" post.