Depending on the radar-target dynamics, the time extent and amplitude of a moving extended target from a radar's perspective may actually change as a function of relative motion. It follows that waveform design should accommodate for the increase or decrease of a target's time extent and changes in amplitude as the target moves towards or away from a radar or vice versa. This paper shows the performance gain and/or degradation of both matched transmit waveform (called eigen-waveform) and the classical wideband pulsed transmit waveform when the effect of motion on target's time extent and amplitude changes are considered.