Grand Turk is grand! Healthy, fishy reefs, only a 15 minute boat ride from shore. All dive ops have small boats with 6-8 divers and local DMs who know and respect the reefs. It's a small island, very laid back, safe, with a couple good restaurant options and small intimate hotels. If you want a laid back vacation with friendly people and good diving but not a lot else to do than relax and read your book after diving, it's great. If you want pulsing night life and lots of restaurant choices and big hotels with infinity pools, stay on Provo.