I have a friend that got one of these. Looks great as single guy operating the baling operation. But the extra work of unloading the hay wagon, I learned from helping him, once full, they get interlocked, and you have to pull the ones at the top off, even if they are more distance away from the unloading elevator. And you have to walk on that mess of bales, not a nice flat surface if it were piled by a second guy on the wagon.
I helped do this as a kid on my aunts farm. Her daughters could throw bales over their head from the bale wagon to someone on the stack, ....real women!