You will love Atlantis IF it suits your vacationing style. Any bad reviews just mean that The Cove was not the right vacation for them. Atlantis is basically a big Las Vegas resort hotel plopped on a beautiful beach in the Bahamas. So, if you like that kind of thing, you will not go wrong. In full-disclosure, Atlantis did not fit our style (i.e. we love the peaceful quiet of Turks & Caicos). However, we had a wonderful time.
LIKES: Open-air and cool vibe hotel entrance. Bathrooms are huge and very well-done. Beautiful beach with calm, turquoise-colored water. Beach chairs are padded and very relaxing. Amazing breakfasts at Mosaic with almost anything you could imagine ($31 + gratuity). Great lunches at the Cain Pool and Sea Glass ($20 for sandwiches). Delicious dinner restaurants (big plug for Nobu). Really fun to hit the Aquaventure water park slides each afternoon (recommend going after 3:30pm). The Mandara Spa was very nice. And finally, the Dolphin Shallow Water experience was very fun.
NOT SO GREATS: The adults-only Cain pool is one of the coolest pools in photos only (not actually in-person). It is hip-hop playing, heavy bass pounding, Club Cove. It's the plastic pool :) It is definitely not for relaxation, book-reading, or even listening to your own music. Also, everything is crazy expensive. Before you go, just accept that everything is very, very expensive. You have to suspend your concept of reality on how much things should cost. E.g. a bottle of water is $4 to $6. Going to the gym is $15. Internet is $20/day. Your hotel bill will be littered with fees. So, you will not have fun if you're constantly thinking about the $$$, because it's just insane.
TIPS: Stay in upper floors of hotel for better views. Go to Starbucks if you want to save a few bucks on bfast (it's still expensive for what you get!). Buy water bottles before getting to hotel.