Arrivng 11 p.m. on an internatiional flight? You'd then have to go through Immigration, get your bags, and go through Customs. Could be very late.

We stayed at the Atlanta Airport Marriott, in College Park, and took a shuttle, but that was 2-3 years ago. It was fine. Maybe there's one even closer to the airport. Even with hotels that have 24-hour shuttles you MIGHT have to call them when you arrive if it's after a certain hour, such as midnight (i.e., they may not be going by the terminals on a regular basis). You can confirm that in advance. You could always use Priceline or Hotwire (Hotwire has amenity icons, and one should be airport shuttle). By that hour you may be tired enough that you'll be willing to pay for a taxi and use the shuttle for your return, though with 4 (?) kids, you may need a van taxi. I'd ask the hotel you choose what they suggest.