Flex disc on coupler/propshaft



Yes Yes I have researched the topic as well. Think the torque settings are 45nm will just check again when I do it. The obvious alignment marks are to be made however I read on a WIS doc that there is actual marks but you would need to clean the surface to find them.
Okay so my question is, who of you have done it yourself as I want to know what brand did you use? OEM Mercedez or AEM...Meyle? or something else?
Is there any difference between the two? I tried checking locally but my dealership didn't have stock of it to show me. I checked a AEM brand here that's imported from Germany, blue box, think it was a Meyle product unsure though. The rubber looks solid and feels in between. Not polyurethane like which I am sure is not a safe compound for this use. I heard apparently that the agents have changed the design into a hard plastic like compound or is it just also rubber?
Sadly the price of one from the agents is way too much and the AEM brand I can purchase is only a 1/3 of the agents price. I don't want to be penny wise pound foolish where couple months down the line it fails catastrophically and takes out my tranny.
Any expert or experienced advice pls members













