Looking at the floorplans, I think the chateau is a nicer setup. The queen bed is walkaround so you can easily make the bed, you gain a couch, and the refer is more convenient to the kitchen area - rather than being pushed out further with the slide of the freelander. With the chateau, you can watch tv from the sofa, with the freelander, you have to sit at the dinette (I know some folks who have installed a tv in the overhead bunk so they can watch from both the dinette and the couch). With only about 1 foot longer, the chateau seems to give you more for the space.
On the flipside, the freelander has slightly larger tanks.
Mileage is tough - too little mileage could mean ongoing issues that have kept the RV parked instead of being used. But too much mileage and you're hitting some maintenance issues sooner. It takes a good inspection to determine if one is better than the other.
Every chassis make has its problems and people tend to have their own opinions of which is better. If you're handy with a wrench, that can make a difference as to which one is better for you.