I am certainly no image expert, but I am really satisfied about the image quality.
On the 3D, LG utilizes the passive glasses, which are really comfortable.
The 3D effect is really well done, with no flickering as with the active glasses.
I am never tired after watching an entire 3D movie. The apps work like they are supposed to. Where this TV is really lacking is in the support of local movies (think MKV saved on a USB hard-disk)
We're in 2013 and the TV still does not understand anamorphic DVD content, which my parents' 4-years-old TV (different brand) does with no issues. Also the Plex app is really poor, so much that in order to use Plex I have to go through a Roku... All in all an excellent buy, as long as you don't need to watch video from your PC library.