The OEM does look very robust. The "Superstat" is heavier than the standard Stant but certainly doesn't look that beefy.

Stant says:

"The power element of SuperStat« is comparable to those used in heavy-duty trucks. Its actuator piston is larger in diameter than the standard thermostat and competitive product. This larger piston delivers 1 1/2 times the power of our standard thermostat and almost 2 1/2 times as much power as the competition for enhanced durability and longer life."

"The opening spring of the Stant SuperStat« thermostat is designed with a load that is 50% stronger than our standard reverse poppet thermostat. This heavy-duty spring helps return the thermostat to the closed position and prevent cold running, even under the most adverse conditions. Features and Benefits"

"Upgrades over OE equivalent thermostats offer more efficient temperature control resulting in faster warm-ups, better fuel economy, and longer engine life."

"Limited lifetime warranty."

I've never had any Stant fail. Not sure of the cost difference of OEM and Stant. I've also never tested the so-called better temp control over standard.