A frustrating vise issue can be when using the metal jaws. Some of them have a slight taper to compensate, but cheaper vises can spring out a little and only hold a piece along the bottom edge of the jaws. With soft jaw faces and using post vises, its a non issue.

I had a made in Japan craftsman vise that I gave to my brother a good while ago. In general, they were pretty nice for being in the affordable category.