"I'm a developer so I know what I'm talking about which means that Apple must be wrong!"<p>The technical changes of bringing a service like iCloud photos must be massive when compared to projects that most of us here work on. Millions (billions?) of users, petabytes(?) of images, support for Desktop and Mobile and Web, and launched worldwide? Seems to me like they've done a pretty great job handling this!<p>I'm a long time user of Aperture and have built up ~200GB of RAW Photos, and there's no way I trust icloud photos to handle this without corrupting things with no backup in place that I can control (Sync != Backup). So for now, I've only setup iCloud photos to work with my iPhone photos (~6Gb, which so far, has worked excellently. I haven't had any sync issues, in fact sync has been pretty quick for uploads/edits/deletions/meta.<p>Of cause, this doesn't mean that issues will become apparent with larger 100GB+ libraries.<p>Personally, Photos is missing power features that aperture had and i used extensively, but the promise of a synced photos library across all my devices, previews and metadata, as a system level service for 3rd party integration is the icing on the cake.