Reviews of OEM BMW thermostat

I was instructed by a friend who had some of m47 and m57, to buy thermostat only original from bmw, because everything else doesn't work as long or good.

I replaced the t-stat with a genuine part and again no luck.

The replacement thermostat came from BMW. No problems this time.

Changed to genuine thermostat, no change. Needle tends to dip on higher load highway driving, but only occasionally. Obd temp is between 77C-88C.