This afternoon, I spent some time compiling a video that demonstrates the lack of performance in a lot of these photo adjustment applications. https://www.youtube.com/watch?v=JX7urEQhzM8 (watch in 1080p if possible) It was both surprising and disappointing. Surprising because Aperture actually performs better than the rest despite it's reputation to the contrary. It was also disappointing to see just how bad some of these apps are on what is arguably a very powerful computer. Admittedly, I'm running these on a 4K display which is a lot of pixels to update, so perhaps others will see better performance using displays with less pixels. Interested what others are seeing on your system... Is it the 4K displays that is killing performance here, or are these apps just dogs?! Anyone else running 4K displays or a Retina iMac that can comment on performance compared to what's in the video?