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Pros
Pro Good introductory tutorial
Pro Seamless collection propagation and back-up
The only thing you have to do to add new photos to your collection is to open the app. Fire up your Android app, your laptop and your desktop with HDD attached. In short time your photos will be saved on 3 different devices, which can be then moved to different locations for increased safety against data loss.
Pro Lots of organizing capabilites
Can organize by albums, by folder, by date, by event (events can be automatically fetched from smartphone), by rating, by people (has face tagging/learning capability), by category, by flag, by place on the globe. Events can have categories assigned too. Can make complex searches by metadata, file name...
All of this does not have to be done on a specific device. You can sit on a sofa and start adding some ratings, clean up bad photos, then go to a desktop PC and do some face tagging. All the changes will be synced between the two devices and all associated devices asap.
Pro Seamless collection size management
If a device (such as smartphone) is going to run out of space, fire up the app. Assuming you've already given to Mylio an occasion to back up the original photos, it will automatically free up space and keep downsized versions only.
Pro Free for the light user up to the intermediate user
Free scheme allows you to manage up to 25k photo collection on 3 non-smartphone devices. Then add unlimited Android/iPhone devices, no RAW editing and good editing functionalities. The intermediate user could be satisfied for a long, long time before thinking to switch to a paid scheme.
Pro Compatible with Lightroom
Edits done in Mylio are compatible with those made in Lightroom. You don't have to import changes from Lightroom, you can actually edit a photo multiple times from any of the two programs.
Cons
Con Requires some basic IT skills and some "time to think"
Mylio is not for the totally casual user. Mylio requires someone who is INTERESTED in organizing and has some patience to fiddle with different devices and takes care of keeping some vault devices powered on regularly, so that the collection is actually backed up. Mylio needs you to have a "home", a physical place where your stuff, your family, your loved ones and their photos will be physically collected.
Con A compromise between portability and privacy
Mylio will not be in most cases ubiquitous as Google Photos, Flickr or iCloud, since offsite sync will only be available if you own one of the paid schemes, and the devices which are in possession of the original data are actually turned on and connected. Think as having your own Cloud storage at home. Some may like it, some may not.
Con There is only one version of the entire collection
If your collection is made of 1000 or 500k photos, it will always appear the same on ALL devices. This means that you can't store a "part" of your collection on a specific device (you could do so by adding different sync policies, but you may be quickly overwhelmed by the complexity of the management).
Con Android app is not optimized
Android app, despite the recent updates, is still unresponsive and somewhat tricky regarding to item selection and navigating the menus. Smartphone's built-in galleries run smoother with regard to just photo browsing.