In this talk we will motivate the description of the 4-body decay distribution B->K*(->Kpi) mu+mu- in terms of a basis of primary observables, so called Pi(') that exhibits a suppressed soft form factor dependence at large-recoil and an enhanced New Physics sensitivity. We will present an updated analysis of the new LHCb data on this mode, focusing on the interpretation of the sizable deviation found in P5' in terms of a large and negative New Physics contribution to the Wilson coefficient of the semileptonic operator O9. We will argue that a set of other smaller tensions seems to be consistent with the same interpretation. We will discuss the robustness tests performed, in particular, on charm pollution. We will also comment on other analysis done in the literature. Finally, focusing on experimental analysis, we will discuss how to control S-wave pollution.