I forgot to mention that when I put the 205/45/16's on, instead of the stock 195/55/16's after a few days, the TPMS gave a warning. After checking my tire pressure, and reading how the TPMS works, I realized that this is due to the smaller diameter. Because the diameter is smaller and the wheel makes more revolutions, TPMS thought it had to be a flat tyre. Anyways, after a reset to the trip computer, everything's fine.
Also over the past weekend, I had my brakes replaced with the original R56 cooper S brakes, as my friend was upgrading to a much more serious R56 JCW big brake kit! 316mm!

So I have now upgraded from 280mm to 294mm and new pads. I didn't have a chance to really test it. I think there has to be 'some' difference!

I believe this should be the most stopping power I'll need for my one

may be I might go for stainless-steel brake lines and dot 5.1 brake fluid to improve the brake feel...