I guess we'll have to agree to disagree. I don't think it's a matter of some people noticing it and some not (though it may be the case in some instances). People have posted screen shots with black bars in a completely dark room and there is no light bleed. And from reading comments from folks owning other brands it's a problem on ALL edge-lit brands at ALL price points. There are however variances in panel quality in the manufacturing process regardless of manufacturer. Add to that there are variances in abuse to the panel in getting it shipped from the plant to your home. A couple of years ago I saw a stack of 5 or so LED TVs laying flat at a Cosco - I wouldn't want to be the person that got the one at the bottom. I've even heard that loosing (as in a very tiny adjustment) the back panel screws or buffering the screen can help significantly.
Follow Up: I'm concerned about light bleeding too, but I'm now very much convinced my chances of getting a TV with minimal light bleed are just as good with the Vizio M series as it is with any other brand including Sony's edge-lit televisions. i.e., I've have read complaints about light bleeding on the highly regarded Sony KDL W900A.
Thank you for making an intelligent post without making insults. I do agree that there are differences in panel quality and I think most of the issues are baked into the design (edge lit). If people are satisfied with what they have fine, it is their call. I really didn't notice it until a couple of nights ago and I have had the TV for over a week. I also think the movie content makes a difference since I really noticed it on a BD disk. If I can get a better set I most certainly will but who knows.