The OEM parts for the air suspension are about $1400 per wheel (taxes included) compared to OEM parts for coil over shocks (standard or sport shocks and springs available) at about $275 per wheel (taxes included).
http://www.lexussouthatlantaparts.com/showAssembly.aspx?ukey_assembly=758013&ukey_make=1082&ukey_model=15670&modelYear=2001&ukey_driveLine=8085&searchString=suspension
I considered keeping the air and just replacing the rear bags but $3,000 for two air bags was hard to digest on a car with a $6K trade-in value. I called Lexus dealers in Naples, Fort Myers and Sarasota and none of the service departments would swap the bags for coils and shocks (for whatever reason). I figured I would be happy with the standard Lexus ride but when the dealerships were not co-operating, I started looking for aftermarket parts and a specialty shop to do the work.
The Megan Kit was $200 less (four corners) than OEM spring and shock parts. The Megan kit (and most other suppliers with product costing more than the Megan kit) offers shock dampening adjustment as well as height adjustment; neither is available with OEM coil over shock systems. The Megan coil-overs have about 4" of height adjustment and 32 settings for dampening.The kit I choose has the softest spring rate of any of the after-market kits I looked at and with shock dampening set at its softest, the ride is very much like the ride in my previous two (non-air) LS400's. Adjusting the shock dampening is easy to do - the dial is on top of the shock and accessing the dial is a 2 minute exercise on the front and 10 minute exercise at the rear. If I want the car to ride like an Infiniti or BMW, it can be done easily.
I really like the look of the lowered car, but my wife doesn't like the idea. I intend to offer the car for private sale when we look for a used LS460 later this year (or next year) and thought the lowered car might be offensive to a prospective buyer. It takes about 30-45 minutes in the shop to adjust the ride height so the next owner can lower the body over the wheels without changing the ride quality (although running the undercarriage into parking lot bumpers might become an issue).
It would be interesting to know whether Sewell (or any other supplier) has proper instructions for de-activating the dash lights (there are some posts in this forum where the after-market supplier has directions to cut wires - which I do not think is necessary).
I have a shop appointment to get the ride height (headlight leveling) sensors re-installed and hopefully will be able to get the headlight leveling working with raked suspension and without the warning lights. I will update my results after that exercise.