i would not trust any apple service to host/preserve my images. just have had way too many instances where images just disappear. and afaik they still haven't really explained the connection between all the celebrity phones being hacked when they were all using icloud (if someone has a link that'd be nice)
To add to this, Apple also doesn't bother to make it clear to users that there are limitations to backing up their photos using iCloud. You can get pictures out of Photo Stream whenever but that's only the last 1000 photos or 30 days. For Camera roll that actually stores the backup of all of your photos, you can only access your backup if you restore it to a new or reset device. If you get a new iPhone and don't immediately restore from iCloud then too bad, you either have to wipe your new iDevice or buy a new one in order to get to your backup.
