Addressing the thermal management challenge of high-performing power electronics is imperative for standardization. While the performance of a conduction plate heat spreader is limited, passive heat spreading alternatives like Embedded Heat Pipes (EHP) and Pulsating Heat Pipes (PHP) can spread heat more effectively and handle higher heat flux. In this manuscript, the thermal performance of two different form factor heat spreaders was compared experimentally at operating temperatures of 20 °C and 40 °C. The EHP was essentially copper-water heat pipes embedded into an aluminum base plate. The PHPs had internal capillary channels of size 1.6 mm. Testing results indicated that the PHP was more susceptible to dry-out compared to the EHP, where no dry-out was observed. PHP showed comparable or lower thermal resistance than the EHP at lower heater powers when the operating temperature was 20 °C. In all other cases, EHP demonstrated lower thermal resistance than the PHP.