The Big Look is a magnifier that is on an arm and hooked to a platform that slides under your machine. It adjusts in all directions easily. I use mine all the time. It not only helps me see the needle area, but also forces me to set up straight in my chair so my neck/shoulders don't ache when I sew.
I figure that any "gizmo" that helps me continue to quilt comfortably is worth owning. If I buy something that I just don't use, I will pass it along.