Before the move - by way of comparison I thought the Marriott Ambassador service was pretty useless (unless one has a unicorn Ambassador and/or gets marked for special handling due to directing revenue to Marriott)
My Hyatt Concierge "EQ", OTOH, is simply fantastic - incredibly responsive, usually within an hour if working hours. Can't be more pleased.
Contrast w/my Marriott Ambassador who until leadership apparently might have lit a fire underneath them, took days or never responded at all.