To achieve optimal performance in the regulation of nonlinear systems, more advanced control techniques are needed. In this paper, three of these techniques are applied and compared in a system composed of three tanks in cascade. The first one is the Nonlinear Extended Prediction Self-Adaptive Control (NEPSAC). NEPSAC is a nonlinear predictive controller and therefore, is based on solving an optimization problem using the nonlinear model of the process to find a feedback control law. The second one is a gain scheduling controller using an array of autotuned PID controllers. This will be the non-model-based strategy. Finally, the gain scheduling approach is used again but with an array of linear model predictive controllers. In this case the predictive controller is EPSAC, the linear version of NEPSAC controller. Comparing all these control strategies, this work deepens in the characteristics, performance, advantages and disadvantages of these techniques to deal with nonlinear processes. It is intended to be a reference guide to choose - from a practical point of view - The most appropriate controller when dealing with a soft nonlinear system.