: Based on previous work of the authors, this paper provides a comparison of two different tracking methodologies for extended objects and group targets, where the true shape of the extent is approximated by an ellipsoid. Although both methods exploit usual sensor data, i.e., position measurements of varying scattering centers, the distinctions are a consequence of the different modeling of the extent as a symmetric positive definite random matrix on the one hand and an elliptic random hypersurface model on the other. Besides analyzing the fundamental assumptions and a comparison of the properties of these tracking methods, simulation results are presented based on a static tracking environment to highlight especially the differences in the update step for the extension estimate.