It must be the rareness and the fact it's done by Atari
Bingo ! You know I love Atari. And I've always found it fascinating when Nintendo and Atari's paths crossed. That's why I love to see the big "by Nintendo" on the DK and DKjr Atari 800 cartridges.....and on the game screen.
And I love the story how it was almost Atari who would have marketed the NES with the Atari brand on it all around the world except for Japan.....would we still have the Atari name today if that deal went through....? Imagine the Atari Wii

And then I discovered the flyer for this machine.....so cool to see Nintendo licensing Atari just for the European market only...it's just.....very special.
Just love to see both logo's on that side-art

And personally, I don't like the Nintendo cab shape that much at all....it's a weird shape and it's uncomfortable for European players. The Atari machines are designed for taller people I guess....but I'm not so sure about this "midi" version.