I spent a long time comparing ML500 and X5. ML500 is a first-rate vehicle with significant improvements even over the 01 (such as bi-xenons) and is larger inside and about 10K cheaper than 4.4 X5. In the end, however, handling was the major factor for me, and there was simply no comparison. The X5 center of gravity is only one inch higher than 5 sedan and the vehicle is clearly designed to compare to a sports sedan (I drove one on X-cross course). I bought the X5.