We find the best Resolution is ‘Scaled’ – see below for the setting.

This will automatically adjust the Guest resolution when you resize the window.

When moving to Full Screen Resolution – you may need to adjust the res to the optimal for your screen. Do this by clicking on the resolution icon (small screen icon – upper right menu bar) and selecting the best resolution.

Below Full screen Resolution on a 27″ Retina iMac

Warning: on Retina displays – resolutions in the 5000K are available – do not use them without a powerful magnifying glasses.