 I have owned five BMW's now including a 2001 3 series convertible, a 2003 3 series, a 2009 Z4 and now the X1.  I intentionally dropped down in size and class of car, so I went in expecting some compromises..but not what I have gotten.  Horribly cramped, the auto engine cut off is terrible, average gas mileage is 7-8 mpg worse than the lowest rating, interior is flimsy and several plastic pieces fall out of their place regularly and worst of all, my side airbags went of with no collision at all as I was taking a corner (BMW dealer has told me this isn't the first time they have dealt with this!)  Add to this the fact that the seats are horribly uncomfortable and I am beyond disappointed. 