I sailed on the Millennium last New Years, and loved it so much that my wife and I are going back in Feb. We had a Sky Suite and had an attentive butler who took care of shore excursions, reservations for the special restaurant, personal needs, etc. They usually bring canapes or hors d'oevres around 4 pm. We told him the first day exactly what we wanted, and had it every day. My wife even treated herself to an in-suite message.
I haven't travelled in a suite on HAL, so I can't compare the level of service, but you do get extra perks.