Just yesterday, I reported that Motorola had finally posted the official update documents on its website for an upcoming update for the Sprint-branded variant of its flagship smartphone, the Moto X, and already tons of reports have been flying in confirming that residents in the U.S. have now started receiving the much-anticipated upgrade. In addition to the latest build of 4.4 KitKat, the update also brings a truckload of bug fixes, stability improvements and speed optimizations for the handset, as well as the implementation of a couple of new features.