After many years of using the CS 6 Master Collection, we had to move to CC 2015. I've ben using Photoshop since version 2.5 (That's 22 years ago) CC 2015 feels like it's always two steps behind me. It has done something strange every day since I've upgraded. Yesterday it opened without any palettes, and couldn't open any or reset workspace. Had to close app and open it again. Most frustrating is the Scrubby Sliders in the Text palette. They rarely but sometimes work. When they do work, they are amazingly slow to update the display, making them useless and unpredictable. The updating of the document display seems strange. There are stripes that don't get updated, or get filled with the wrong bit of memory or something. GPU rendering issue, maybe, I've tried it both on and off. Program still seems slow on a 12 Core Xeon MacPro.