Grid-connected photovoltaic (PV) systems require accurate modeling and efficient control strategies to ensure reliable operation and optimal power extraction under varying environmental conditions. Achieving a balance between modeling accuracy and computational efficiency remains a major challenge in PV system simulation. This paper evaluates two widely used modeling approaches: the detailed switching model and the average-value model, both implemented in MATLAB/Simulink under identical operating conditions using maximum power point tracking (MPPT). The models are compared in terms of MPPT efficiency, dynamic response, power quality, and simulation time. Results indicate that the detailed switching model provides higher accuracy and better dynamic performance, particularly under rapid irradiance variations, whereas the average-value model significantly reduces simulation time and computational complexity. The study highlights the trade-off between accuracy and efficiency while providing guidance for selecting the most suitable modeling approach according to application requirements............ This scientific manuscript was presented at the sessions of the International Renewable Energy, Gas, Oil and Climate Change Conference "iREGO" in the period of April 25-27, 2026. Tripoli – Libya............. Keywords:.......... Photovoltaic Systems, Grid-Connected Systems, Detailed Model, Average Model, Simulation, Maximum Power Point Tracking (MPPT), Performance Evaluation.