I like the reaction jaw to move straight in and out, with no oscillation of the jaw at all, on the way in, and out.This keeps things square in the jaws when they are clamped. I also like the reaction jaw to move instantly when the vise handle is turned, a sloppy handle makes it tougher to get things clamped when you are jigging things up in the jaws. I probably do a bit more fabrication with my vise then most guys, but, if you spend time with a file working parts in a vise, or, polishing small parts, it is easier and quicker in a tighter vise. The Wilton vises have that precision, most other vises do not. A fair point is a utility vise in a maintenance shop might not need that precision, but, it doesn’t hurt a thing if it is there. Most maintenance shops don’t have great vises installed, however.
I’ve seen Japanese copies of round bar vises that come close, and the York vises, built in Europe, do, too.