10.9.4 is a vital update if you operate a new Mac Pro and use Premiere Pro. The two were incompatible for many users, self included, when attempting to render sequences using Open CL. The machine would crash frequently, create glitches and strange patterns in video. For weeks, angry Mac Pro users, self included, reached out to Apple, Adobe or other users looking for a fix. With 10.9.4, it appears the fix has arrived.
Thank you, Apple.