Turks & Caicos can not be compared to the Pacific. T&C are at the top of the list for the Caribbean although it is actually the Atlantic. The coral life in the Pacific and the fish life are not comparable.
The Pacific is a much older ocean, for one thing you may find 400 species of Angel fish in the Pacific while finding about 4 in the Caribbean. With corals, there are about 62 species in the Atlantic compared to 900 in the south Pacific
I've been to T&C as well as the GBR, if you are on the GBR from Lizard Island north it can be incredible.
T&C is incredible next to Aruba or Freeport Bahamas or St. Thomas. Of course you must also have some insight on where you are to go in T&C., Turks would be good, also west Caicos.