Definitely better off through Ft. Lauderdale than Newark. Have been there and done that. And, it's the Blue 'Plus' fare that includes a checked bag, so a correction to my earlier post. They've been messing around with this so watch the 'total' fares carefully. Delta may provide a better price to SXM. The advantage that Jet Blue once had fares-wise and baggage-wise have all but disappeared in recent years, but overall I have had good luck with them when flying to St. Maarten, Cancun, etc.