Hi,
After having both items right next to each other in the workshop, I took a closer look and compared them.
Kolbenmasse (incl. Bolt:
AFN: 777g
AUY: 789g
Bolt: Approximately 4g lighter when used with the PD system.
Bolt diameter: the same, but different design (tapered material recesses at the ends).
Compression height: equal.
Piston guide (piston liner): approximately 3mm shorter in the PD model.
Mulde: apparently identical.
Connecting rod bearings: identical except for the locating features.
Connecting rod: The PD engine (as is generally known) uses trapezoidal connecting rods, which means that pistons and connecting rods can only be used in pairs.
I find it interesting that the PD piston, despite the cooling channel and shorter guide, is heavier

.