I've never noticed any difference between a DV and an EV certificate, and I'm working heavily in this field. The difference is useless unless you actively look in the address bar to see if there is a difference. Most users won't.
I think we learnt that lesson with 'check for https in the address bar' and now we have HSTS instead.
or on the browser integration. If chrome/firefox decide to remove this distinction tomorrow, the whole business aspect of it will die.