I extensively tested both MDX and X5 on the (paved) back roads around Calgary, and for me the X5 was a clear winner despite the $$$ tag. Mind you I was comparing fully equipped MDX against X5 without the adaptive drive, since in Canada to get it you have to buy the active steering too, and I wanted to stay away from that as far as could. The cornering, acceleration, breaking (especially this) ... everything is better on X5.

Now, I must admit that certain things about interior I liked better on MDX. Acura doesn't have anything close to iDrive but the commands are simple and sufficient I dare to say. And if some people here don't like the BMW rear view camera - you should see the one in MDX, it is a total joke.

I guess I can go on and on, but you get the picture, I liked BMW better.