Great color palette, but sometimes has weird functionality and/or doesn't always work. Examples: 1) on Facebook, with Owl enabled, Messenger is not functional (messenger window is hidden, and trying to access it from the list of contacts on the right causes the whole page to scroll down several screen-lengths). 2) very weird: some search terms disable the Owl extension on the Google homepage. Example: any search string with "pdf" returns the normal blazing-white Google search results page.
Summary: good in a pinch, but very buggy.