If changed, and a single piece driveshaft is installed, gets ride of flex discs for solid u joints, gets rid of the center support bearing, and lighter, less rotational mass.
Mb liked the rotational mass in ours, hince why they used such a massive flywheel.

I don't know about you but I like the idea of a chunk of steel holding my driveshaft on alot better than a piece of thick rubber.
Have you ever seen a flex disc in a truck, hahaha
Flex discs are alot cheaper to manufacture and install at factory, doesn't mean they are the best.