Sounds like a minor detail, but when syncronising (uploading) files to the cloud, SignageStudio editing is disabled until the upload completes. Some sort of background upload feature would allow a user to continue working on a timeline (or alternative campaigns) whilst the background upload completes. A short video upload may lock out editing for 10-15 minutes – and I can only drink so many cups of coffee in a day

Alternatively, FTP access or a standalone web-uploader would be cool. I'm assuming that media items are catalogued in the database when uplaoded, so FTP may pose some technical issues.
p.s. +1 my vote for a more intuitive way of organising of media items (and retaining the current filter/folder whilst navigating between timelines/screen types etc.)