My X5 sat with arrnot front struts for 4 years on the bump stops and aired right up.
The guy I bought it from got a suspension fault shortly after replacing them and the shop faulted the Canbus and the rear dropped.
He got so fed up he drove it home and parked it, sat for 4 years!
I cleared one fault with my handheld and the fronts aired right up, the back didn't (plausible distortion) and drove 50 miles like I was riding a horse at full speed.
The fronts stayed aired just fine, I cleared all the faults with inpa when I got it back (cluster communication was issue) and the back came right up.
I replaced the rears with arrnots too and promptly drove it 1200 miles straight, that was almost a month ago and everything has worked flawless.
For those bags to be completely deflated for 4 years outside in the California heat, air right up and not leak. WIN!
Arrnot is the only aftermarket bag I'll use, I also have a P38 Range Rover and that's pretty much the normal replacement for everyone.
I'd suspect some people don't know if they have sport suspension or not, it's worth decoding your vin before ordering replacment air suspension parts.
Also if you're doing it your self you'll want to set all your heights, mine was so far from factory it was comical.