I've been doing some digging. Now I don't read Japanese but from what I can decipher, the Mini-Xj is not actually a new version. It's just a normal Mini-X that comes with this made in Japan parts kit:
Steering linkage
2 brackets to mount a servo
Upper rear arms to adjust rear camber
4 low friction diff bushings
6 low friction wheel bushings
4 plastic wheel nuts
As far as I can tell, the chassis will NOT be black or changed in any way.
This is not a bad thing! It just means that hop-up parts are on the way. So go buy one. I am