Hope things have cooled down for you with the Behr. It's just my opinion, but Behr is the only radiator that I would put in my MB.
Regarding the fan clutch. It's my belief that these devices are too often mis-diagnosed. You read stories about people sticking pencils into them while moving. etc. and that may not be a good test, let alone somewhat dangerous. They activate at a given temp. and rpm.
Check out what MBDoc had to say in this thraed: