Recently was news that VE now rapidly opens. But for me it was not working. Every time I open a new wiki page and opened VE, for VE loads big js-file. I have long been using the visual editor in the firefox. Disable add-ons did not help, menu-options-privacy-delete cookies and delete cookies for ru.wikipedia.org not help. For me, it helped privacy-delete cookies and delete all cookies. Maybe it will help somebody else.
@Elitre (WMF): Thread:VisualEditor/Feedback/Feedback/reply I do not know because of what it was, but now, after removing all cookies VE opens quickly :)