This paper presents a comparative experimental evaluation of three control strategies for angular position regulation of a Vertical Take-Off and Landing (VTOL) system: a conventional Proportional–Integral–Derivative (PID) controller, a Linear Quadratic Integral (LQI) controller, and a proposed nonlinear PID (NL-PID) controller. The proposed strategy extends the conventional PID structure by introducing a nonlinear gain that dynamically modulates the control action according to the evolution of the tracking error. The controller gains of the nonlinear PID are obtained through a genetic algorithm optimization process based on the Integral of the Squared Error (ISE) and maximum overshoot. Experimental evaluation is performed through three tests under different operating conditions: a normal test, an uncertain physical parameter test, and an external perturbation test. The angular position response and control effort of the three controllers are analyzed, with tracking performance quantitatively evaluated using the Integral of the Squared Error (ISE), Integral of the Absolute Error (IAE), and percentage overshoot (PO). The results show that the proposed NL-PID consistently provides the best tracking performance among the evaluated controllers. In the normal test, the NL-PID achieves the lowest ISE and IAE, with reductions in ISE of 16.34% and 7.25% compared with the conventional PID and LQI controllers, respectively. Under an uncertain physical parameter, these reductions increase to 19.89% and 7.54%, respectively, while the NL-PID also exhibits the lowest IAE and percentage overshoot. Under an external perturbation, the NL-PID achieves the lowest ISE and IAE, reducing the accumulated squared and absolute tracking errors by 12.06% and 15.65% compared with the PID controller, and by 22.50% and 35.29% compared with the LQI controller, respectively. These results demonstrate the potential of the proposed nonlinear PID to improve angular position tracking performance under different operating conditions while preserving the simplicity of the conventional PID structure.