To expand a bit on what ruralcarrier has told you, we've stayed at Mary's Boon and quite like it. We often choose to spend our beach days there being 'boonies' for a day, but that said, we would not enjoy staying in the below-grade rooms there and I would just suggest you get a room location in writing. Many say the room doesn't matter but truthfully, to us it does. Beyond that, we really like Mary's Boon and have chosen to stay there a few times over the years.
The obvious, booking the two extra days at La Playa, I'm sure has been considered and vetoed for whatever the reason. Did you consider the Holland House Beach Hotel on Front Street? I haven't stayed there but it would put you in the heart of Philipsberg and right on the beach there, making for access to lots of fun places along the Boardwalk to eat and celebrate.
The month of February can be very busy on the island, particularly the middle of the month, so I'm thinking Sonesta Maho, which is possibly all-inclusive, or Pasanggrahan, both of which are considered hotels as opposed to timeshares might also be doable. We haven't stayed at any of my suggestions within the past five years but we've eaten meals at all of them and we enjoyed each place for different reasons when we stayed there. <img src="http://www.traveltalkonline.com/forums/images/graemlins/handshake.gif" alt="" /> <img src="http://www.traveltalkonline.com/forums/images/graemlins/handshake.gif" alt="" />
.
