I had the dealer lift my trailer and add shocks. We go on some very rough roads with no trouble. Admittedly, we roll at about 5 mph to avoid damage to the suspension, but the clearance is amazing. (I am not sure we have to go so slowly, but I am notoriously over-cautious.)
The only downsides are these:
First, a higher center of gravity. I have not noticed any handling problems as a result, but it has to be true that there is a slightly greater risk of rollover during sharp high speed turns. Bottom line -- it's not a sports car.
Second, the higher trailer must also generate more wind resistance. A lower trailer takes greater advantage of the "wind shadow" of the tow vehicle. Again, I have not seen a measurable difference, but it has to be true.
Third, I have built wooden tripods for my jacks so that they can better stabilize the trailer. Otherwise, they would barely reach the ground and were on "tiptoe," if you can visualize it.
Fourth, the steps are now too high from the ground for DW, who is only 5 feet tall. So we bring a step-stool to help her on that first step.