When comparing DockbarX vs Plank, the Slant community recommends Plank for most people. In the question“What are the best Linux app launchers?” Plank is ranked 7th while DockbarX is ranked 9th.
Ranked in these QuestionsQuestion Ranking
Pro Great plugin to help blend in to XFCE4 panel
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.
Pro Easily customized
DockbarX has inbuilt settings that allow the user to easily customize the look of the dock, from changing the text color to the background color.
Pro Easily the best Win 7 taskbar functionality
If you want a combined launcher/manager, a la Win 7, this is it.
Pro Solid and lightweight
Pro Simple and minimal
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.
Pro Third party themer available
An additional third party app has been developed that allows theming the dock without the use of any extra resources. This is great for those that are not using elementary OS and the elementary tweaks extra.
Con Not actively updated
Less than a dozen updates since 2014: https://github.com/M7S/dockbarx/commits/master
Con No right click menu for some apps outside of elementary OS
Other file explorers and terminals (those not found in the default elementary OS) do not have any right click menus for the dock meaning it is impossible to launch multiple windows for certain file explorers or terminals.
Con Poor workplace awareness (cycling windows)
When configured to only show apps on current workspace, cycling an app open on multiple workspaces will switch workspace focus, update the dock and often leave you to cycle another app.