To clarify, I don't have air suspension on my 2015 Limited. They are special struts called Nivomats that use hydraulic oil and special valving to automatically level. All self contained. As for how the truck has held up, it's been relatively low drama so far.
I have replaced both turbos one at 100,000 miles and the second one at around 180,000 miles. I had the throttle body replaced under warranty at 100,000 miles as well. I have replaced coil packs and plugs often. I had to drill a weep hole in my intercooler to stop multiple cylinders from misfiring. I have never installed a catch can. I have had one front wheel bearing die and replaced it. The power steps still work and I lube them religiously. Power fold mirror on passenger side just went bad. I'll be replacing it. Heated and cooled seats keep having that one pin burn out. I've fixed it once with a new harness, I'll need to do it again. It's a thing with these. I have $1200 into a 93 octane race tune by ZFG racing and it's wild. Truck is very very quick. I used ForScan years ago to turn off my seatbelt chime, turn on my LED fog lights as Daytime Running Lights, add two flashes to my lane changing turn signals from 3 flashes to 5. I also made some changes to my instrument panel. I have GTR Ultra LED head lights and high beams and swear by them. Lifetime warranty from The Retrofit Source. 4WD still works perfectly. Upgraded to drilled and slotted rotors and stoptech brakes. Happy with them. Not sure what else to say....wish someone had real info on replacing Nivomat rear struts with aftermarket bilstiens.