We purchased a Sleep Number bed for our home several years ago and love it. It is the best mattress we have ever had - would pay double the price for another if need be. (No - I don't own their stock - just love their product.) We didn't know that they made a Sleep Number bed for RV's - so we purchased a Bear Bed air mattress several years ago for our fifth wheel. It is a very good mattress, but not quite as good as the Sleep Number bed. It is great to increase or decrease the firmness of the mattress as needed. I wouldn't be without an air mattress.
I bought some vinyl and covered the plywood bed base in the RV. The vinyl makes it much easier to slide the mattress forward to put clean sheets on and no chance of getting a splinter in your fingers or in the mattress covering.
Air mattresses are much lighter - so I get to pack more stuff in the closet to make up the difference. LOL
Only thing to remember with RV air mattresses is that you need to let some of the air out before traveling in high elevations. After you arrive in the high altitudes - pump more air back.
Hope this helps in your decision making.
Deb