with gnome-fallback and classic gnome shell, we had gnome applets available, but not in Unity. There was a system monitoring applet there that I could see may CPU and network bandwith used. I'm pretty sure that I can not have the same applets in Unity, at least not yet, from Can I use GNOME applets in Unity?.
Gnome-Window-Applets is a Gnome panel applets that substitute maximized window title and buttons.Window Title and Window Buttons are essentially controls for windows that are placed on the Panel instead of a window. By default they only control maximized windows, but can be configured to control any focused window.
The GNOME Shell redefines user interactions with the GNOME desktop. In particular, it offers new paradigms for launching applications, accessing documents, and organizing open windows in GNOME. Later, it will introduce a new applets eco-system and offer new solutions for other desktop features, such as notifications and contacts management.
Cinnamon along with Linux Mint offers you the traditional GNOME 2 layout that is built from GNOME Shell giving a much more modern foundation. Cinnamon 1.2 has many new cool features, the desktop effect, desktop layouts, new configuration tool, the applets,and much more. A host of changes, bug fixes and improvements went into this release.