Live Preflight is also a common source of slowdown.
Have you installed the 7.5.3 patch?
7.5.3 is installed.
All - known - preflight options and seperation preview is deactivated.
Looks as if this API plugin makes the difference: APIDToolAssistant_Mac_CS18.104.22.168.50
As soon as I remove it from the plugin folder, ID seems to be quite faster.
Should this be the solution?
well, to doublecheck the issue, I installed the API again and the lag is still gone. Strange! Don´t know, what happens here.
Plugin might have become damaged...