I was wondering if it's made this way on purpouse, by design, or it's a bug (I think I don't remember it being this way before): controls' axes (Main, Root...) are not aligned to the scene's axes orientation - to move Main forward you need to move it by the X axis instead of Z :/
This was done intentionally. By having the Z-axis to the side, it allows proper mirroring of controls on both translation and rotation. On traditional rigs, if you have mirrored behaviour for controls, rotating the left and right control simultaneously is symmetrical. But if the controls can also translate, they will move in opposite directions.
A good example of this would be on the face where most controls translate and rotate. With the traditional rig setup, rotating both the left and right mouth corner controls would keep the face symmetrical and any key frame values would be the same. However if the mouth corners are translated in object space, one would go up, one would go down. And the translation channels would need to be animated with one having negative values and the other having positive values. This is not ideal. But in RRM3, both translation and rotation are mirrored by having the last evaluated channel (Z) aiming left and right and by introducing a negative scale to the controls on the right side of the rig.
Joint orients are still the the standard x-axis for twist.