The Limited V8 was the only 4Runner that could option the auto leveling rear air spring susp.
This system is one of the best on the market. There is an approx 4" height difference between the low and high setting. You can lower the system to load and wash the vehicle. You can raise the system for off-roading, water crossings/flooding, and going over driveways.
Where this system really shines is when towing. When towing you can lower the vehicle and back up to the trailer and when lined up simply hit the high setting and the ball moves right up into the trailer hitch. You can also use the system to adjust the approach and departure angle of a trailer and the rear of the vehicle. If backing up a steep driveway you can raise the rear of the trailer by lowering the rear. Then after the rear of the trailer passes you can raise the rear so the hitch clears. It works very well!
No matter what weight (within recommendations) you carry and/or tow the system automatically levels the vehicle to maintain ride dynamics, on the fly. You can see and feel the ride difference even when there are just passengers in the vehicle. Even when empty, the ride is better (smoother with air springs instead of steel coils). In my opinion, it is worth its weight in gold (especially if you tow).
Koz