I have stayed in several beach clubs in Sottomarina and Playa del Sol is certainly one of my favourites: minimal look, distant sunbeds and a quiet appearance, you don't hear the conversations of your sunbed neighbours, little noise. The cost of two sunbeds and an umbrella was 6 euros less than average.
Very nice restaurant, fresh food, varied menu with different possibilities even for me as I am gluten free.
The only flaw is the squat toilet which I personally don't like, but overall very satisfactory.