The main thing is "American Made", something special in everyone of them because of that fact.
I was at a flea market a couple of years ago when a guy drove by slowly with a huge old Wilton vise on the back of his pick-up. He said he want $35 for it, it probably weighed 100 pounds. I had to bite my lip to keep from saying "sold". I have two vises on my workbench now, no room for another vise, especially one that big.
I looked up that size Wilton vise when I got home, they sold for $450 new.