L.K.
We went for Christmas 2007? So a few years ago and my kids were older so this may not be helpful to you. I personally didn't care for the Atlantis. I enjoy swimming, but Atlantis is nothing more than a huge water park and casino. My kids were 13 & 17 at the time and they thought it was fun, but it's not on their list to go back. The food and drink were very expensive.
And I really felt Nassau was really kinda dirty. I remember thinking I was thankful we were not staying within the city.
I can say, been there, done that, don't intend to go back.