Since I have one large seperate partition for all file storage and assign it as /home to every distro i install i created a permanent directory called Media in /home/Media. Ubuntu Tweak has a tool to set my default storage directories for pictures, docs, videos, etc from whatever the home directory is for the distro i installed to the matching one in ?home/Media. this is a great convenience. Even were i to not add repos through it, it's package manager lists the more common files i use without having to remember them our go searching in synaptic, they are just listed there, a short list of most people's favorites. also it has an automated cleaner for uneeded files, the file download cache, config files and old kernels. these tools are quite useful. Also it allows me to show advanced feature in the nautilus menu, fix the theme appearance while in root, allows me to change the default files to launch for different files readily, allows me to add shortcuts, manage templates, manage scripts, has abuilt in desktop recover/backup tool, allows me to make some adjustments to compiz, gnome and window manager setting. and more. It is a useful tool even if you never install another repo of any kind. The repos it will add by default are debian repos for swiftfox, opera beta and official, google stable source, deb thumbnailer, iphone ethernet driver for usb, play on linux, and skype. It also has a feature to install updates for your system
it's a great tool for so many reasons, don't be fooled by the name.