There is a significant difference between the MDX and the X5 whether we're talking about 1st or 2nd generation. Acura is near luxury, BMW is luxury. Having driven both, the new MDX has comparable performance with it's 'Sport' package. Comparing apples to apples, the MDX will almost always figure to be about $10,000 less on a similar X5 package. Acura uses a lot of plood, lesser quality interior pieces. Although I've really enjoyed the 1st generation MDX and I feel the new one is great, I feel in the long term it evens out b/c of resale value of the BMW.