I'm going to add a Harbor Freight xy drill press vise to this list. One of the worst pieces of junk I have ever owned. Terrible backlash, worse screws, non parallel jaws, axes are not square, just an utter waste of material. I have had it for several years now and just can't make myself use it at all. It takes up a lot of precious shelf space.
I was so fed up with it I tossed it in the trash four days ago. Just today I thought of a possible use of some of the material in the vise. Tomorrow I will fish it out of the trash and cut up some of the cast iron. I do not have high hopes for the quality of the cast iron, but if it works, then the vise was not a total waste of money. If it doesn't work out, I will still cut it up then toss the rest.