Thanks for your reply bcredliner,

I completely understand where you are coming from in regards to the ride quality being about perception and the possibility of it being 'worse' after the conversion. My gut tells me that it won't be worse, most likely the same if I had to place a bet.

As for the towing capacity, I suspect there 'could' be a slight reduction in maximum safe tongue load. However, since I don't plan to ever haul anything that even comes close to the maximum towing capacity that shouldn't be too much of an issue. I can just mentally tell myself that the maximum tow capacity is 25% less than what it is and be fine. But lets face it, you should know if you are overloading a vehicle's capacity without having to weigh your trailer. You can take it for a little test drive and check out the way to body sits after hooking up and tell if it makes you nervous or not. So I think at this point the towing impact is somewhat of a wash.

I may just start a separate thread discuss my particular issue to see if anyone has any suggestions. From the research I've done it truly seems like it could be either 1 or 2 air shocks in the front, leveling sensors, or the control module. Reading about people being so sure they figured it out only to see that they didn't is pretty disheartening when it comes to keeping the air components. If I had only the rear setup, I would probably work on keeping that as it would seem that the cost exposure is somewhere around 60-65% (estimate) of what it is if you have the four corner system.

You mentioned, "The devil you know is better than the devil you don't know". I could stand by those words as well, the lesser of two evils as it were. With that in mind, this is my first vehicle with an air suspension. I would definitely call the air setup the 'devil I don't know' and a common coil spring system as 'the devil I know'. The primary concern here is not having any experience with Strutmasters components. On the flip side, it is possible to source out all of the parts as OEM parts, use OEM shocks/struts and OEM springs. However, I don't know if there is an OEM rear spring for the 4.4i sport setup. Seems like all of those had at 'least' rear leveling system.

I will be buying a bigger jack soon and doing a much closer inspection on the rest of the components. Current floor jack isn't enough to lift the E53 reliably.

Side note: The front driver side sagging issue that I am experiencing is intermittent. some mornings its 3/4" low, some mornings its exactly where I left it *shrug*. When it is low, most of the time as soon as you open the driver door it inflates back up in like 2 seconds without the pump kicking on.

Thanks again for your feedback bcredliner,

Justin