One advantage of the wood floor vs dirt is it makes it more portable, PLUS, no need for an apron to defeat digging predators. In fact, I doubt anything short of a bear could get in. And maybe not much larger than a mouse or small snake on the small end. I doubt even a least weasel could find a way in. (when pop door is closed) So overall, about as predator proof, including rats, as you can get. And again, unless something is attached to it, very portable. A person could use this and a section of electric poultry netting and move it around at will.
I have moved it once. From the shed where I built it about 50 yards to its current resting place. It skimmed along nicely and didn't even scuff the grass.