I havent had any probs with them at all...
Both of mine turn on at the same time, and also cycle with the air-con.
The car is always running cool.
Rollin has 2 temp switches, one comes on and if it gets a little hotter the other turns on. I will be getting his switches soon.
You may need to put in a cooler thermostat, as you dont want the fans to turn on to cool, and the thermostat to be closed still.
Performance gains, well at least you dont get the aeroplane sound effects anymore!!!
I got 0.6sec of a qtr time, but i put an XR cam in and thermos... I think the fact that it doesnt have to spin the
fan may have helped!!!