LG WRman Sherlock here!
What you want in a TV is entirely dependent on you. Some videophiles can see even the most minute differences in picture quality between two different TVs, and most others cannot. So then if you can't tell the difference in picture quality between two different TVs, the next thing you should take a look at is the features. Would you rather have active 3D or passive 3D? What about the applications available for each TV? These are just some of the questions you should be asking yourself.
The best thing to do, as many people have already said, is to look at all the TVs yourself personally. Someone might tell you that the picture quality of this TV is better than that TV, but if you can't see the difference, what does it matter to you?
Finally, since I am LG representative after all, if you have any questions at all about the LM6400 or any other LG World Record TV, feel free to ask!
LG WRman Sherlock, out!