Red-eye flights aren't too bad and they get you into MBJ in the morning. We always try to take one out of Denver. It does make for a long day, but half of it is in paradise. Get some good travel pillows and take them on the plane with you. I can never sleep anywhere, but in a bed or couch and yet, I can get some cat naps with a good travel pillow.
While the diving isn't fabulous in Jamaica, the Negril side is better than the Ocho side, so since you haven't been there I'd suggest giving it a try. We've been to both CN and CSA, both are fabulous you can't go wrong with either one. CN is smaller and more boutique style while CSA is on Long Bay where you can roam on the beach forever.
Juliann & Jeff
Jamaica Soon Come