Terrible Performance
This update ruined Logic. The interface looks great, but the performance is not. My computer is quite powerful (4 core i7, SSD, 16 GB ram) but I cannot play back audio and change parameters at the same time. (For example, turning down the master volume during playback causes the audio to pop and click, and the spinning rainbow wheel of death to appear). If you decide to upgrade, do yourself a favor and BACK UP THE OLD VERSION OF LOGIC FIRST.
Apple865 about Logic Pro, v10.3