I've got about 400GB / 60,000 items that I am thinking about uploading to iCloud*. Has anyone gone "all-in" with a similar amount of data? I've got a Macbook Air 128GB, iPhone 6 64GB and iPad Mini 2 16GB that would all run an optimised library. I am interested in what the performance is like across different devices for an optimized library - both OSX & iOS. I'm currently playing around with a smaller, cca 10GB library to see how it works, but I am curious if the performance would be the same with a library 40x bigger. Questions: How is scrolling? Searching? Smooth? Opening photos/videos from within 3rd party apps? Do videos stream as they load or do you have to wait for them to download fully first? Do they download in full quality if the setting is to keep an optimized library? *I do intend to keep and maintain at least two local copies of all my data on external drives.