Yikes this thing is as thick as the MZ x500 would be hard to find a case for it.....

Its a €150 medelli, where they replaced the samples... Yet the instrument feels like a toy... Samples are okay at best...

I wonder what their marketing & target strategy is with this model?

No marketing at all, its been around for about 2 years now...

Deebach also has a pa600 which uses the same samples...

In this video (also from Musiker Lanze aus Erfurt) they explain everything about these 2 systems

They are a spin-off of former Wersi, and probably they are somehow trying to make use of inhouse-developed samples with a certain emphasis on typical Wersi organ sounds, hoping to arouse the interest of Wersi fans.
I still think their sounds are a mixed bag, some might be better than the built-in Korg PA600 sounds...
I listened to their so-called "1930 Grand Piano" on Soundcloud, that sounded like a very simple sample with a lot of simple low-pass filter added for the pianissimo - quite ridiculous. Other pianos sound good, but again not breathtaking. It's a difficult endeavor to find a market for this package...

Having watched a part of that Deebach demo, their strategy and some details have become clearer.
He states that all the sounds are newly sampled, and one emphasis is on achieving a live sound with a lot of pressure, e.g. in the drum samples.
Another thing, and they stretched this nearly to the ridiculous, is a "natural" sound which they intend to achieve by detuned (!) samples, e.g. in case of the very detuned piano he plays during the demo. I think in principle he is right, but this piano really sounds like a western honkytonk, it's too exaggerated.

One important difference between the sound package for the Korg and the Medeli-based MAXX is that the MAXX does NOT have the identical sounds, but uses HARDWARE sound generation, i.e. the filters are hardware-based. He had explained that in a demo in 2015 already, and this means it is not just a Medeli with a different software, but internal parts have been exchanged, too.