(Quasi) LPV control methods and more generally L2 gain control methods, referred to as nonlinear H infinity control methods, are usually applied in order to ensure reference tracking and disturbance rejection. In this paper, we exhibit a counterexample that reveals that these specifications can not be ensured by these methods. We then propose a new LPV based approach in order to a priori ensure these specifications by combining the LPV method with the incremental L2 gain analysis of nonlinear performance. Its benefit is illustrated on the counterexample.