I haven't handled the Luigi case at all, but I just received my Zhou case yesterday, and the quality seems perfectly fine. In terms of fit, I wish that the horizontal piece of leather that ran along the upper portion of the back of the body went a little higher above where it says 'PLAY' and 'MENU' on the camera, and then fit neatly in between the bottom of the eyepiece and the button/screen frame, but I don't know if making the leather that thin to fit through that eyepiece spot would work in terms of manufacturing the case like that, as well as the longevity of the leather in that area (And, looking at the Luigi case in your review, I see that case has the same design, albeit for the Thumbs-Up). So this design might be as good as it gets, but still it's very well made and looks great. A hole in the bottom to allow use of the tripod socket would be a thought as well.
Leather is of very nice quality (and smells good too!), stitching is excellent, and I think it's good value for the money (I can't really speak to it being a 'knockoff' or not). Of course, when it comes to using your M8/9 for a job that would involve quick battery and memory card changes, the case would definitely get in the way. But for casual shooting, vacation etc, it would be fine.
BTW, I noticed that you seem to have four little pieces of tape on the corners of your LCD screen - what are they for?
