I ran a colder Bmw thermostat and it did helped keep temps in check and most consistent compare to the normal temp Mercedes T-Stat's. What I didn't like was how long it would take for the engine to warm up. And in the winter the car would never be get to operating temp and using the heater would make it drop to 75C.

With the new thermostat setup its nice to be able to run a hotter thermostat so the car is up to temp within 2 minutes.