--- XPlus 3/ XPlus MIX 3/ XPlus 3 Dark --- The most noticeable difference between the XPlus 3 and XPlus MIX 3 models is the lighting effect. The XPlus 3 delivers an absolute black tone more effectively, while the XPlus MIX 3 excels at warm tones, providing softer light that highlights facial and skin details more clearly.

For example, in a photo taken in a dark room, the XPlus 3 produces a deeper black background, whereas the MIX 3 makes the face appear brighter and more evenly toned. In outdoor photos under sunlight, the MIX 3 creates a more realistic and natural effect.

Additionally, there are some differences in hair, skin, and material rendering.

Original Source: https://civitai.com/models/118111?modelVersionId=1134093