Looks like nobody has responded to your post. I removed the air suspension from my 2008 Limited. The system uses level sensors on the wheels, but they get out of alignment and that causes the computer to get out of whack and overcorrect the air flow to the bags, causing an hilarious rockin' ride. If your bags or hoses leak, that will create the same kind of experience. Replacing the original system is over $1000 which seemed like a waste for a 15 year old vehicle.

Nonetheless, mine crapped out so I removed the XRES (or whatever it's called) and installed Bilstein shocks and lifted the front to level out the profile. Entire project cost about $300. If you tow, you will want to get heavier duty shocks in the rear. The suspension may be bit less comfortable, but I don't experience any added sway or roll feeling without the air suspension. There are some buttons and alarms that need to be deleted or ignored, like the level indicator on the dash will stay level the entire time. The only loss for me was the ability to raise/lower the rear end when adjusting to trailer heights. But none of my other tow vehicles do that, so I'm pretty good at getting trailers lined up.

I read a lot of threads about replacing with conventional suspensions, and decided to do that instead of spending the extra funds for OEM replacement. I'm glad I did and since my system was wacky, I'm really glad I replaced it all with conventional suspension.