You have two choices -- Crystal Palace or Atlantis. CP is much smaller and quieter. But, they have converted to continuous shufflers on almost all tables (by now it may be all tables). They open tables only as needed, so depending on time, maybe crowded or limited to only a handfull of tables. BTW this is the same management as Mohegan Sun in CT.
Atlantis has more tables and you could find six deck manual shuffle. Did not see any continous shufflers the last trip(few months ago).
To be rated at either place you need to play $25 min. The comps are better at CP, but nothing to write home about. I would not go to Nassau for gambling alone, although a lot people from FL do so.