I have flown Delta from Charlotte through Atlanta, Insel from Charlotte through Curacao twice and lastly, Delta from Greensboro through Atlanta. My preference is Greensboro (local airport) with Delta and I will willing pay a few extra dollars for this option. The Delta flight from either GSO or CLT (and I assume Raleigh) essentially gives us an extra day diving due to its arrival/departure times. Insel from Charlotte has not been too bad but it leaves late so arrives late in Bonaire and the change over in Curacao can be an issue. Missed or full plane, lost luggage and since it is the last flight that night its the next day before you or your luggage arrives in Bonaire if you miss it. We nearly missed the transfer our first time, we were escorted at a jog through the Curacao airpot to meet the plane. The luggage arrived the next am, a minor hassle since we could not dive that night anyway. And of course, the flight from CLT is an older plane.
And if you get the American Express Delta card, you and 3 others booked with you will get first checked bag free each way and earn miles for future trips.