Due to outstanding search strength and well organized steps, Genetic Algorithm (GA) has gained high interest in the field of overloaded Multiple-Input/Multiple-Output (MIMO) wireless communications system. For overloaded MIMO system employing spatial multiplexing transmission the authors evaluate the performance and complexity of Genetic Algorithm (GA)-based detection, against the Maximum-Likelihood (ML) approach. They consider transmit-correlated fading channels with realistic Laplacian power azimuth spectrum. The values of the Azimuth Spread (AS) and Rician K-factor are set by the means of the lognormal distributions obtained from WINNER II channel models. First, they confirm that for constant complexity, GA performance is same for different combinations of GA parameters.