We are senior couple and have about 1200 miles on the highlander.
We are averaging just over 24 MPG, and on our three trips of about 90 miles each we got right at 30 mpg.
This was driving mostly on rural highways, with about 35 miles of interstate at about 72 to 73 MPH and about 62 MPH otherwise.
The wife thinks the seats are not as soft as our '04 Grand Cherokee, and the passenger seat is manual only, but that has already turned out to be a non-issue.
In addition to the very good mileage we immediately noticed how much more quite it was than the Jeep.
It is close to the same size as the Jeep but can seat 7.
We've had six adults in once for a short thirty minute drive and no complaints
Very good mileage, quite, more side to side front feet room, no bump in second row floor, the ability to lower the second row of seats from the rear, the separate controls for rear heat and air, the moon roof with a solid screen, the sliding second row seats, and the not to high, not to low step in height.
The cruise controls are taking some getting used to, and perhaps more padding in the seats.
Also, if the vehicle was, say, 8 or 9 inches longer with that length added to behind the third row seats would be great, although that would undoubtedly increase the price.