We have rented from St. Martin Rentals (Lydia and Felicia). Yes, they are initially slow to respond, but when you arrive and are on the island they are very, very responsive. After renting from several agencies both on and off the island, their on island care is superb.
Also, Jeannie from Shop and Drop works very well with Lydia and our food/drink order was easy to coordinate.
We always rent a car, and some nights we just walked to the restaurants in Orient Village.
Good luck and have a great time on your trip.