I believe which ever PS you stay in you are allowed to use the pools in the others .For me i think the pool area in PS3 is the best of the bunch ,and from the pool area the seafront walk way that run between PDLA and Los Cris .For me PS3 looks far less dated in comparison to some of the others .Best beach (imo) is quite near to the PS apts,Playa las Vistas and from where this beach starts its 20/25 min walk along the seafront walkway ,if you want the sunday market at Los Cris add on a further 10/15 mins ................
Have a fantastic time ,this is definately a better part of PDLA where you have chosen to stay