I like plug-ins that are functional and do as they promise. This is one. Install and use. Can't beat that. I dislike having to alter code to get a simple task done (or fumble over complex settings or odd set-ups). If I am taking the time to write code, then I should be building my own site. WP is supposed to sidestep that process. How does a plug-in that requires coding to work fit that design? I am not sure. This plug-in meets the WP intent: Simple. Efficient. Functional. Ready to go.
For artistic-minded, demanding WP enthusiasts the visual of this add-on may be too pedestrian (you can make some aesthetic changes). Sitting at your page bottom it may not be as appealing as some twitter buttons or other links, but buttons are not supposed to overtake design and content. This one doesn't. If you want users to be able to send/share/bookmark your pages and posts easily, then this is the plug-in for you. Note: A rare 5 stars from this user.