Recently purchase CPO with only 28K on it. Absolutely love it. You can't beat BMW CPO - they had the car ready in mint condition, the warranty is excellent, and I still have over 20K left on included maintenance and 0.9% financing (unheard of for CPO!). The X5 handles like a dream and I personally think this model is better looking than the redesign in 2007. The interior is top notch and the power seems way stronger than the HP rating - that speaks to great engineering. No rattles, solid like a tank. I'm actually getting up to 26mpg on highway trips and 18mpg average overall.
The best thing about this car is that it puts a smile on my face every time I drive it - something I didn't get with my last Acura.
The blower seems to stay on pretty high even when the temp is reached on auto climate control. A lot of brake dust, but not really big deals.