It is confusing but there are Two westin properties in Cancun.
First, there is the Westin Cancun Hotel and Spa. This is a Hotel and is located at the far/extreme souther tip of Cancun Beach. It is very far away from almost everything (although it is closest to the airport)
Second, there is the Westin Lagunamar Ocean Resort - this is the condo I am renting at. It is in the heart of Cancun beach and right across from La Isla Cancun Shopping Village - could not be more convenient!
It should be noted that the Westin Hotel guest cannot use the condo pools. At the condo, there are several pools, multiple hot tubs and it is right on the beach of course. There is also a waterslide.