 3.0 V6 is notably quicker, smoother, quieter than the four cylinder 2.0. Unfortunately, like most German cars, the engine size drives the price up!  But the engine usually accompanied by a couple of other "nice to have" sport features help you rationalize the difference.   I've always been a "coupe" guy, but in my current situation, I'm drawn to a moderate sized cross-over SUV.  Therefore, I wish it had a little smoother ride and less body lean in turns.  However, I'm quite pleased with my choice of the Q5, but now wonder about an SQ5.  Nicer yet!  Waiting on new model update expected in 2018.