My buddy has one, I went for a ride not too long ago
I was amazed at how different his coil spring car, with new coil springs compared to my over 200,000 mile air springs.
His car would bounce and rebound going over expansion joints, so much that my head was bouncing like a bobble-head doll.
On braking the nose dived so much that his spoiler under the bumper cover has been almost ground away.
When he is in the car by himself, with me following the car leans to the side like that ship in the poseidon adventure.. just before it flipped over.
His car has less than 10,000 miles on his coils, and mine has OVER 200,000 on these air springs..
my car rides better than his.. hands down.
and..my car doesnt lean to the side like a ship about to capsize.
and.. my car doenst' bounce and rebound over expansion joints.
I have seen both sides of this debate and MYSELF.. I'd take my 200K sirsprings over coil springs.. any day.
My buddy asked me if I wanted to drive it.. I couldn't get past the crappy ride in the passenger seat.. I had NO desire to drive the car after that.