Received the update few days back on my G3 but no significant improvement in UI responsiveness. Its still the same - little bit jittery.
4.4.2 ??!!! seriously?!! all other flagships are on 4.4.4....
And yes, i tried an LG G3 in a mall and its UI was not that responsive besides having SD801! hope they have fixed it.
best of luck to G3 users!!