I had a 2011 x5 35d and traded it for a 2012 x6 35i.

I pretty much hated driving the 35d. I had come out of a 7yo x5 e53. The 35d drove too danged big by comparison. Highway driving was excellent, but 80% of my driving is in town where the 35d less than shines.

Driving my x6 is awesome in almost every way compared to both my old e53 and e70. My passengers prefer the x6 too. I have only two complaints: I hit my head almost every time I get into the car (and I'm only 5'4") and the rear window fills only about half the rear view mirror. I've learned to more than accommodate for the rear window by relying more on the side mirrors. I've had a whole lot less 'close calls' than I have in years.

Does the 35i have balls? Certainly not if you compare it to the 50i. I'm an ultra aggressive driver and I would obviously prefer the 50i, but I learned how to drive on a manual xmission over 30 years ago. Using sport mode and/or manual, I can make that car fly. Just using your foot in regular mode, it's a little lack-luster at slow speed.

Why didn't I get a 50i? I'm just too lazy to purposefully put myself into a position to have to fill up my gas tank after only 250 miles. When i drive a full tank out in town in my 35i, i only get 14-16mpg (aggressive driver + Lots of short trips and stop lights = BAD gas mileage -- I got only 18-20 in town with my 35d) what do you think I'd get out of a 50i? 10?? Put a 35 gal gas tank on that puppy and I'm there!