"Load space" isn't a thing, but that does affect your tractor's turn radius. It will up fuel consumption a small amount, that's fancy but mostly empty space and the weight premium isn't that bad. And we now have husband/wife teams on the road, and a good wife deserves some comfort. I'm sure you'll also see some people use that cab and body on a shorter frame, omitting the hitch, and now you've got a million mile diesel RV.