I'm new to this forum.. I live in South Africa.. Thinking about getting an ST..

Just wanted to know if anybody had taken on a Cooper S yet..?? And the result??

I live in Johannesburg which is at high altitude so the ST is going to lose 18% of its power so the Cooper S should really whoop the ST up here at Joburg coz it has the supercharger.. Just interested to know how bad I might get hurt..??