i had a meyle one, came with the car when i accquired it. started leaking about a year ago. went with the behr since they are a very trustable brand and supply original parts for mercedes.
compared the two pieces and the meyle one didnt seem like it was put together as well as the Behr clutch IMO
quick test to test fan clutch- spin the fan as hard as you can by hand. if it spins more than 2 1/2 times, chances are the fan clutch is shot
to actually verify its not functioning- roll up a big "blunt" of newspaper and with the engine idling, jam it into the fan blades. if the fan stops, the clutch is bad