This viewer adds a variety of graphics/rendering related fixes.
Note: for Mac displays with HiDPI support, retina display mode will be enabled by default. This will generally give you a sharper display but a lower frame rate. If you want to disable HiDPI display, go to the preference settings page Me->Preferences->Graphics->Advanced Settings, and uncheck the box “Enable support for HiDPI displays (requires restart)”; then restart the viewer.
BUG-226768 [Love Me Render] Mesh Child Prims in Linkset are now Yellow instead of Blue
SL-10952 Look at performance impact of selection outline changes