Even though the hurricane season does run from June 1 to November 30, it is rare when there is a storm in June, so that should not be a consideration. They are both beautiful islands and each has its own characteristics. The Bahamas are much more laid back, easy going, beautiful beaches and water is outstanding. Aruba on the other side has much more night life, is more commercial/touristy. There are lovely beaches there too, but not with the peace and solitude you get on Grand Bahama. So, a lot depends on what your looking for. I've been to both. If I want to just get away to relax and unwind I go to the Bahamas. If I want a more active vacation, I'd go to Aruba. Aruba has many high rise hotels, casinos and "glitter" experience. Grand Bahama has flip-flops, sand between your toes and minimal glitter. You may need a week of unwind after a week in New York.

If flight times are important to you, from New York, Aruba is around 5 hours, GBI is around 2 1/2. That may or may not be a factor in your decision.