 Owned the 528 with M sport package, The sport package is a must if you really wanted to experience true BMW performance.  Definitely consider snow tires if you live in wintery climate.  This car is great HOWEVER I hope you make good money because you will need it... an oil change alone is $135.00.  All I can say is it doesn't get serviced that often but when it does be prepared to shell out the cash.  You are better off to have your "out of warranty" Beemer service at a reputable european car service center.  back to performance it is 2nd to none.