We have stayed at both properties as exchangers. Villa del Palmar is out of the way. Although more has been built in that area we didn't like the location all. We own at the Royal Sands and we like its location. In addition we always rent a car and my husband is bilingual. Also, as exchangers they wouldn't let us use some of the amenities on the property!! Personally I feel that is BS.
Westin Lagunamar is in a wonderful location. The villas are lovely and you are in walking distance from many restaurants and a grocery store.
IMHO Westin's Lagunamar wins hands down.