If Hyundai doesn't create a luxury brand for the Equus - I'll give it one shot. If I don't like my service experience, I will move on. I am used to Lexus, BMW and Cadillac service - not Hyundai service.
I'm not sure what you mean by "Cadillac service" because every Cadillac dealers I've ever seen were just plain old GM dealers that sold Caddies and only had one service counter.
I've also known enough people who've owned Lexus, BMWs, Infinitis and MBs to know that the only difference between their service department and the "regular" brand's service departments was the ego stroking that went on there. The actual service was mostly sub-par but they didn't notice because of how good that little tube of KY made them feel while they were being taken advatage of.