Have only had the car now for about a week. Less than 500 miles on it so far but so far so good. Just got a hitch put on it and the all weather floor mats and mudflaps. Turbo definitely gives it a bit more pep - but you should definitely drive for yourself to decide if the premium (and drop in gas mileage) is worth it. One gotcha that I have not seen mentioned is that the Turbo requires premium while the 3.0L engine can run on regular. Compared it with XC-60, RX350 - and decided on this for features and drive.
Bluetooth, nav, XM, adjustable power lift gate, sunroof, ability to call with phone but not have to xfer call to car like with MDX system, OnStar, entry and locking w/o having to deal with keys or keyfob
Fix gas tank filler angle so don't have to hold while filling up at certain stations; improve fuel economy and come out with hybrid version like RX450H