I have fitted a
JCW strut brace to my cooper D. Fitted easily, the only slight
mod i made was to install a strip of foam tape between the brace and the engine cover to stop a slight buzzing noise at certain engine speeds. I really like the look of the genuine
JCW strut brace and i got it for £115 from the dealer. Bargain

As far as any difference to the drive/handling i have driven a good few laps of the Nurburgring with and without the strut brace and i can honestly say i have not noted any improvements.