In this paper, we compare a new practical lattice reduction method, Seysen's algorithm, with the existing LLL lattice reduction approach. Seysen's algorithm considers all vectors in the lattice simultaneously and performs global search for lattice reduction, while the LLL algorithm concentrates on local optimization to produce a reduced lattice We also study their performance, when combined with linear detectors (Zero Forcing, MMSE and extended MMSE), and successive interference cancellation (SIC) detector. For MIMO digital communications, Seysen-based linear detectors achieve the same diversity order as the optimum ML detector. It outperforms the existing LLL-based linear detectors. Moreover, Seysen requires less computational time than the LLL scheme. However, this gap disappears in SIC scenario: Seysen-based SIC detector functions the same as LLL-based one, due to the efficiency of SIC itself.