2013 E550 PLM Heat Exchanger Upgrade


I am in the process of rebuilding my 2013 E550 Coupe.
I am in need of a new heat exchanger and I would like to know if anyone has used the PLM or any other aftermarket solution?
I am most looking for info on if this is a straightforward swap...
I figure I am going to pay $300-350 for an OEM part. May be worth it to just spend $500 and get a "better" part.
Also, does anyone of the schematics to take the dashboard off?
I appreciate any help/guidance.


