I looked at the MDX before buying the d as well. I thought it drove pretty well, but as soon as I got in the X the difference was obvious. My wife is the definition of a cautious, slow driver, and even she was blown away.

That said, the main reason I ruled out the Acura was the horrible, immobile headrests that are tilted forward and put my neck in a weird position. Not comfortable, especially on long drives.

Now obviously I prefer the X5, since I drive one, but the MDX is not the minivan some of these posters are making it out to be. It came out first in this Car and Driver comparison, linked below. Granted, it's from 2007, but the model is still basically the same. It was one of the factors that led my wife and I toward our 2008 MDX.

BMW X5 vs. Acura MDX, Cadillac SRX, M-B ML350, Lexus GX470, Volvo XC90, VW Touareg, Land Rover LR3 - Comparison Tests

Back in 2008 and 2009 MDX was the darling of automotive pubs but recently I have seen not so favorable reviews. As you say the car is essentially the same. Could be because the refresh came when most other luxury SUV/SAVs were mid cycle:dunno:

You can't always buy based on what car reviewers say. What qualifications do they really have? Many of them praised the 2005 Acura RL when it came out, but it's still a subpar car compared to the competition and poor seller in general. Brand wise, Acura isn't even a top tier brand, their VP even agrees.
X5 or bust. What else would you expect from an X5 forum?

That was also before the new generation of iDrive. Many pubs would discount even the best BMWs because they just couldn't figure out iDrive. At least now they say its as good or better than the competition and don't hold it against the BMW.