Be SURE that your external monitor's input is set to "PC" rather than "AV". I am using a thuderbolt to HDMI adaptor to connect to my monitor's HDMI input. The default setting for this is "AV" by which I think treats the signal as a TV 1080p resolution rather than a monitor 1920x 1080. Even after forcing the MAC to send a RGB signal, the text remained blurry until I switched the input to PC.
Also, make sure that the monitor display is set to RGB rather than YUV mode (TV mode).
Про "обращайтесь в суд" мне пока ни разу никто не писал.