yes, the brand new 520d would be a better buy compared to the demo 520i..but since its a collective decision (meaning family), the diesel has been vetoed out..anyway, bought a brand new 520i instead..got a very good offer from Quill PJ..if you are looking for new F10, i suggest you go to Quill and ask for Ivy or Michael..very helpful and generous..
Anyway, thanks for all the advice!