How about a right click on the desktop? I have a very fast computer with no bloatware on, yet it takes half a second for the desktop context menu to appear. When I do this repeatedly. The first time takes 1 second or more.

Compare with a right click menu in a browser which is instant.

HKEY_CURRENT_USER\Control Panel\Desktop > MenuShowDelay set to 100 (ms) close regedit, reboot.