Users can easily drag and drop apps to the dock for easy launching. Any app that is added will stay on the dock until removed manually. This makes for a great way to have all of ones most used apps in one place.
DockbarX has an available plugin called "DockBarX Xfce4 Panel plugin" that allows DockbarX to blend in seamlessly with the XFCE4 panel, which is great for XFCE users due to the limited options of the default panel.
Plank is a good choice for those looking for something simple that just does its job well. There is no UI for options built in to the dock as to change anything those options will have to be accessed through a text file.
Other app launchers have a feature where they remember often used searches, so say one searches for "Chrome" often, just by typing the first letter "Chrome will appear first in the results due to it being used so often. Krunner does not have this feature, which means everything needs...
Users can choose to launch a stand alone Cairo-Dock session where the dock also serves as a taskbar where all apps are launchable such as in any other DE session. There is a composited version and one without.
AWN comes with a big selections of applets such as a CPU monitor or clock or trash bin. This means one can easily turn the docks functionality into that of a taskbar. There is even an app launcher applet that will group all of ones apps in one place just like a start menu.