SINCE THE LAUNCH OF THE XF BACK IN 2007, JAGUAR HAVE HAD A VEHICLE THAT HAS CONTINUED TO WOW PEOPLE NOW, AS IT DID BACK THEN. AS THE OLDER, WISER BROTHER OF THE XE, THE XF KNOWS THAT IT STILL HAS TO STAY ON ITS TOES AND BRING A PERFORMANCE TO THE TABLE, BUT DOES IT? SIMPLY