If you get the spring and damping rate right, it rides smoother than stock. I know mine does.
As for aerodynamics, ooops. MPGs are the penalty, not ride quality.
My lift has made the ride smoother, especially over bumps in the road & washboard.
I know that pictures never do an obstacle justice, but this hole is 40" and was one son-uvva-gun to hop through. Departure and breakover angles made it impossible to take this line before the lift.