I was just in Punta Cana a couple of weeks ago as well (although not at the Westin--stayed in the Bavaro Beach area). Regarding the seaweed problem... from what I understand from others who have been to PC numerous times, the seaweed only does that once a year (and guess what time of year it does that?). I've only been the one time a couple of weeks ago, so maybe others with more experience can chime in, but perhaps this wouldn't be a problem in December when the OP wants to go.