UPDATE:
Driving today, I was seeing coolant temps in the 97-98 range. Definitely higher than I am used to seeing. I decided to replace the fan clutch.
There is a lot of chatter in the BMW forums that Sachs makes a better clutch than Behr, so I got the Sachs.
Opening the box, it is marked as Made in Germany, a good sign I think.
The installed fan clutch could very well be the original one, judging from the markings.
There was oily residue, the clean spot in the middle was made by my finger to confirm it was oil and not plain dust.
Installed the fan along with a new AC belt as the old one had cracks already.