MJBMW

Hi everybody, First, I am happy to write my first topic, hoping that I learn more about BMW. Now let me ask you this question, I have an old bmw e39 1996 525i, and the country that I live in has some bad roads forcing me to go to the mechanic many times. I searched for BMW e39 525i 2003 or 530i, but I saw BMW e38 728i 2001,which one do you think will be better? (In terms of maintainance, power and fuel economy) *It would be better if you experienced them both Your opinions are appreciated :)