... without prejudice !!! ... found this rather than posting the link ...
not my words and mainly because of the photo of the two side by side ...
I have 5 GM vehicles with both types and touch wood, or in my case touch real carbon fibre,
the main leather difference remains to be just visual ... so far ... 
What is Mulan Leather?
Mulan leather is confusing for many reasons. One of them being that Disney released a movie that might confuse people as to why leather is named after any movie or what the leather has to do with the movie at all. Whatever the case may be you may find yourself making a choice between Napa leather and Mulan leather. If you find yourself in this position then you might also have to ask yourself., "do I know the difference between the two and do I or should I care?" We will examine the issue in the paragraphs to follow below.
What one is right for you?
(OEM) Leather comes in two types. It can come as either Napa or Mulan. Both of these terms are confusing similar to the difference between OEM and aftermarket. If you are experienced in the industry or are a person who has bought their fair share of accessories then you may not have as much as of a problem. However, the beginner, who probably does not know the difference between OEM and aftermarket probably will not know the difference between Mulan and Napa leather.
We have read some people that say that Napa leather comes from the belly of the animal which is softer and accounts for the less grainy feeling of Napa leather. However, we can neither confirm or deny that this is true.
We can confirm that Napa leather does tend to feel smoother than its counterpart, Mulan leather. A side by side comparison gives you the full story.
Mulan Leather on the left and Napa Leather on the Right
The amount of graininess becomes apparent when side by side with the Napa leather. The question becomes if the difference is noticeable.
The difference is noticeable under two circumstances. 1. The person who is feeling the leather is sufficiently educated to understand that there is a difference in the two leather types or is generally aware that the two types of leather exist at all. 2. The two leather types are close to each other.
The truth is that the choice of leather comes down personal preference and how much, "keeping ahead of" the Joneses the owner is trying to stay. The viewpoint of most aficionados is that Napa leather is better for the sheer fact that it tends to be much smoother than its brethren, Mulan leather. If you are trying to impress gear heads or a car show then you need to get Napa leather. Otherwise, you might find that you prefer the feel of the Mulan leather for a variety of reasons. You might like the texture of the leather. You might have had a parent that liked to wear leather boots or something leather and it was textured. If this is true for you then Mulan leather might be the right choice for you.
