Photo Stream is a mixed bag. This feature automatically backs up photos taken on your iOS device to all your other iOS devices and to your computers too. While handy, it only backs up your 1000 most recent photos, so you have to manually save photos you want to keep on your computer to prevent them from being automatically deleted. There's no obvious way to share photos with other users, as you can with rival services such as Flickr, either.
We have mixed feelings about iCloud. It's a good start, but many elements of it need refinement, especially as Google and Microsoft integrate the cloud ever more tightly into their rival operating systems. If you have security concerns about iCloud, it can be disabled entirely but sadly you can't selectively enable it for only some apps.
