Performance of simple PI and model based (IMC) regulators for plants with recycle, are compared in control schemes with and without a recycle compensator. By considering different dynamic characteristic of the process, it is analysed in which cases the adoption of a compensator is necessary to eliminate completely the effect of recycle streams, both for set point tracking and for disturbance suppression. The robustness of the compensator in the presence of parametric uncertainty in the recycle model is also examined.