It depends on what you mean by 'plenty power' but, regardless, the 35i has flexibility that the 2.8 atmo can only dream about. I don't disagree that the 2.8 is 'bulletproof' or, at least, as close as you can get.

Here in Australia, the new X3 only comes with the 35i and the 20d engines initially but I guess BMW will add to that depending on demand. The X1 already has both the 25i and 23d engines so they would be the logical range extenders.