Used TMO via digicell. works great but you have to make sure your phone locks to digicell as you get near STT it will switch to TMO and St Thomas has poor coverage from TMO as of last Summer.
Hot Spot works, but slow.
Have traveled many areas of the world using TMO the last 2 years and love it, has saved us thousands over ATT. Just the last 2 weeks I was in Jamaica, Haiti and DR using TMO. The service is 3g, you can pay extra for 4g.