Blackmagic Cloud: The reason we switched to Davinci Resolve. Easy and CHEAP collaboration!

One of the main reasons, anyway. For a minimum of $5US/mo (currently) any number of editors can work on the same shared project. It also seamlessly handles making and uploading proxy files, or the original files if you have the space for them. Non-proxied files, like music and photos, are also synced. Works with the free version, too.