This is my 5th Lexus, and I have previously owned the LX 470. My GX has almost all the great amenities the LX did, but because it is a little smaller, much easier to manuever. Not to sound sexist, but this vehicle fits a man. My wife likes it, but prefers her RX 350 AWD. And that is just fine with me! I am averaging just over 18 MPG. From my frame of reference, that's decent. If I had wanted great mileage, I would have bought a Prius. The ride is great, the stereo surround sound is great, and it is very quiet. What else could one ask for?
Since I have physical mobility issues, the back up camera is great. The nav system is much better than that of our 04 SC, as are the touch screen options. I also find the voice activated commands very convenient.
The only improvement that I see could be easily made is to add a center console similar to the one in the LX. It offers more storage space, and is a better arm rest. Also, it would be nice if the rear side windows were automatic, as in the LX. But really, I am grasping at straws to find a problem