I have owned a BMW X5 4.4i for 5 years and have had minimal problems with it. I have never had a problem starting the car, even in sub zero temperatures in VT. The performance and handling are great, but the gas mileage is poor. While I have owned BMW sedans previously I believe that the X5 definitely stands up to BMW's good name.
Very hard to believe on your comment. I went through all kinda trouble from first year, but it was OK, still under warranty and many recalls. To me the Hyundai SANTA-FE is a much better SUV than the X5.