I find AT&T works well for me almost everywhere on the island. I am in Coral Bay and generally get 4G service. Little Cinnamon is about the only beach I can think of that has no service and Shipwreck the only restaurant. Be sure to set your service to AT&T and not automatic or you will pick up a boat phone or BVI tower in some cases. My business depends on my availability, and I am able to function most places. Of course, AT&T towers do go down like anything else here. Sun spot activity has degraded the service over the last month, but still has been somewhat usable.
Worked fine for me,,
of course I was on vacation ,and unless it is an emergency..
Used primarily for receiving calls from the girls to pick them up from their shopping !
Ive used both ATT & Verizon on STJ, the ATT is much better, only really issue was out on the East End, got a ot of roaming and picking up "LIME" - which I assume was the BVI's
You'll find several past threads advising Verizon and other non AT&T cell users to buy AT&T GoPhone "burners" just for use in VI. That said, AT&T is the probably the best way to go. Watch for those BVI towers on the North Shore!