HI Froz - Christmas in July on the 25th so I think most PR's will depart on the weekend after the Thursday - count on at least 5 days of celebrations. Villas are relatively easy to come by that time of year and are less expensive - but I wouldn't wait too long if you like Mahoe Bay as that does fill up around that period. The weather is actually nicer than Florida that time of year as the most humid month is usually October. Most bars and restaurants close Sept and Oct.

Flights are quite easy - if you can do MIA to STT you can take the ferry to Road town or VG (depending on the day of the week) which is far less expensive than flying into SJU and chartering a plane (or two if you are more than 8).