The LG LN5700 LED TV has the same screen as the LN5400, but comes equipped with Smart TV features and motion interpolation. The viewing angle is great, but the contrast and black levels are sub-par.
The LG LN5700 LED TV is basically the same as the cheaper LN5400, but with an added smart TV interface. If you do not need this, save yourself some money and get the cheaper LN5400. Both have the same picture quality, which means they perform well in a bright room and not so well in a dark one.
The contrast on the LN5700 isn't good, which results in grayish blacks. This TV isn't the best option in this price range for a dark room (the Samsung F5500 performs a lot better).
The viewing angle on the LN5700 is really good, without any discoloration. Half the maximum contrast was present at 37°.
The motion blur is slightly worse than the average LED.
It supports 24p playback without judder and it also has the option to turn on the soap opera effect.
The input lag is higher than the similar LN5400, but it shouldn't be noticed by the majority of gamers.