I would try towing a trailer that is loaded as you will be using to see what happens to the height when there is tongue weight from the trailer and if trailer tows correctly. If it will meet your needs I wouldn't go back to air suspension.

Most posts here are not in favor of air suspension. I like the air suspension and have not had any problems with it. I like that it compensates for any load. For your needs that would mean the hitch would always be at the same height making it less critical about how you load the trailer, would have less tire wear and handling wouldn't be compromised as much.

Ride is one of those personal preference things and I haven't driven one changed over but I can say I have done considerable modifications to the suspension of my 4.6 to improve handling and have never considered removing the rear air suspension.

__________________
X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas