Have received mine and have tested it a little. And here are some thoughts etc:
Some observations:
Quite heavy.
of the 4 driving wheels, the two middle also flexes up and down.
The motor seems to be a standard one. Visually similar to others. And also marked 324467 + HH0222 (gearbox might be slightly different)
the gearbox is lubricated with a white grease, definitively not
66626 (same with other newer locomotives)
did not observe any issues with 360mm metal track or metal turnouts.
Marklin managed to set the volume “lausterke grundrauchen” to a sensible value, 120.
Slow driving improved after a decoder calibration. And I could tune down the minimum speed to 3.
Note: Reverse requires a little more throttle on the CS3, because of how it is set up from the factory.
this can be "solved" by adjusting the "Correction Factor Rev." from 80 to 128(same as forward) (cv95). (personally, I prefer forward and reverse setting to be equal)
Pros:
drives nicely on a wide radius K track (when it’s even).
not too complicated to open, but be aware of the connected wires
improved dynamic smoke chamber design. It is now possible to mostly empty the chamber with a syringe etc.
fairly good sound project.
Cons:
needs a very even track, and spins easily on M track.
Does not like old M curved turnouts (5140) and 5100 curved R1 track, or K track 2221 .
I find it unusable on R1 radius.
and I notice as I write this that Märklin still has this sentence on the English product page:
“The locomotive can also be run on the 360 mm / 14-3/16" radius (Radius 1) if the clearance gauge is ignored.”
Some pictures for those who like that.
The motor and decoder

The decoder board with the circuits for the dynamic smoke generator:

The dynamic smoke generator:
https://hovland.net/bilder/mj/R5_B2090.jpgEdited by user 21 October 2022 19:55:37(UTC)
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