Even the LG G Flex didn’t impressed for the poor resolution for a 6-inch screen, that was only HD 1280 x 720 pixel, the phablet managed to be popular by its design, for the curved case shape and for the semi-flexible case.
Anyway, it seems that the LG G Flex users will have soon another reason of happiness, as an User Agent Profile suggest that the phablet will receive 4K video recording and 120fps slow-motion video along with this Android 4.4 KitKat update.
These features will be available just after the update to Android 4.4 KitKat, and you don’t need to do anything else. It remains to see when this new update will be available.