Swack, I got two Agie wires and an Agie 45L precision ram. The AGIE'S are 73'and 77' models and still hold a location of a few tenths.The truth is that ball screws on wires don't wear
like a bridgeport's.Wires will have a die block of 10 to 150pds mounted on the table,where a mill would have 1000 to 1500pds. Agie from day one has always had larger and more precise ball screw than its competitors. This is why there's still a market for older(80's) rebuilt Agies.
Now with my(76')E10 Charmilles ram, I know just what your talking about. I have to figure an adjustment of .005 when I tighten the head.But,it has its place and it still burns quite well.
Long story short, wear can be a factor depending on the owner and manufacture of machine.