Sorry to disagree folks, but St. Thomas is NOTHING like Houston. I can't believe that analogy. I live in the "big city," too, so I know pretty much what a big city is and is not. And I LOVE St. Thomas. I've been going to the Virgins for more than 25 years and have always enjoyed trips to both St. Thomas and St. John. St. John, in my opinion, is one of the prettiest (if not the prettiest) island in the whole of the Caribbean. The people are friendly, too, and there is very little crime. Yes, it can be expensive. But it also has some of the cheapest places to stay in the Caribbean (Cinnamon Bay and Maho Bay campgrounds are gorgeous spots that some families come back to year after year).
And the added bonus of either St. Thomas or St. John is their very close proximity to the British Virgins -- Tortola, Virgin Gorda, etc. -- where you can easily take a day trip to any number of other islands and cays by ferry. In fact, on a clear day, you can head for Mountaintop on St. Thomas and see more than 20 islands and cays...beautiful spot. St. Thomas does have some traffic in Charlotte Amalie, especially on days when cruise ships arrive, but I've never had a problem with the traffic and, in fact, find that on cruise ship days you can get some really good deals in the downtown shops.
St. Croix is a lovely island, too. There are several excellent restaurants in Christiansted -- expensive, but worth it. And there are some pretty stretches of beach, but, after hopping around all over the Caribbean, I just wasn't impressed -- either with the best resort on the island (the Buccaneer) or the best snorkeling spot (Buck Island); we found both disappointing. Just my opinion.
If you're interested in moving, however, you might go to www.vimovingcenter.com. This site has excellent information for all three of the US Virgins, as well as individual stories told by people who have made the move. Be sure to read these stories -- some are humorous, some offer great tips, and others will motivate you one way or the other -- to move or stay put. Good luck!