Another quick preference is Zoom Line Thickness. This preference is designed to help you see your line weights by emphasising thick lines. The more you zoom in the more it emphasises the thicker lines.
This elevation has some lines thicker than the others, but with Zoom Line Thickness not activated, it is very difficult to see where the heavy lines are.
This is the same elevation with Zoom Line Thickness activated. It is now easier to see where the thick lines are on the elevation.