Terrible
If you leave your spot early there’s no way to tell the system that the spot you’ve just left is now vacant. So it won’t allow anyone else to use the now available spot.
On top of that, if you, having left your spot early, now try to park elsewhere, it won’t give you that option (presumably because the phantom you is still in the spot you thought you’d left.
If I could give this zero stars I would. It’s pathetic.