I did speed runs with a Traxxas Rustler with a brushed Titan motor and XL-5 ESC using a traxxas 8.4 volt NiMh battery vs a Traxxas 7.4 volt lithium 7600 mah battery and the NiMh battery was significantly faster. Granted the NiMh battery had more voltage so not quite apples to apples there.
As...