abstract: In the last few years, an extremely powerful method has been developed to study the statistical properties of a dynamical system: the functional approach. It consists of the study of the spectral properties of transfer operators on suitable Banach spaces. In this talk, I will discuss how to further such a point of view to a class of two dimensional partially hyperbolic systems, not necessarily skew products, in order to provide explicit conditions for the existence of finitely many physical measures and prove exponential decay of correlations for mixing measures. To illustrate the scopes of the theory, I will discuss how to apply the results to a family of fast-slow partially hyperbolic maps. This is a joint work with Carlangelo Liverani.