Try hitting "d" with the mouse hovering over the viewport.....have a dig around, lots of settings to help greatly improve what you are seeing in your images.
iouzzr I just hover my mouse on the edge, the preselection blue highlight looks very bad. It looks like dotted line instead of solid line. Is this normal?
Im also seeing worse quality of highlighted cyan edge compared to selected orange edge It always seems thiner and aliased (with all visual negatives that brings) regardless of width and antialiasing settings of the display options