While it's possible to stay at one end of the island and dive the other, I don't think it usually makes sense to plan to do it that way, certainly not every day. You'll be getting up really early to make the boat! Decide what area you want to dive and stay someplace convenient for it, or decide where you want to stay (if that is more important, like if traveling with a non-diver who really wants to stay at a big hotel in the middle of stuff) and plan diving from there. I could see maybe heading west a day or 2 if you really wanted to do some of the easy shore diving available there, or heading east one day if you're stuck staying in the west but really want to see what the East is like.
Are you considering staying at Compass Point and diving someplace else? If so, I doubt that's something that happens much. It's the package of Compass Point and Ocean Frontiers plus proximity to the East end sites that gets the good reviews, not just Compass Point itself - it's a nice place but really you stay there to dive there. With one of the best dive ops right there going to some of the best sites on the island, people don't drive to the other end of the island to boat dive typically lesser sites with someone else. Now if you have more than a week you might consider staying some time on each end of the island.