One of the feature that I LOVE about Topstyle is the ability to check for usage of any selector in your style sheet. Basically, it checks to see if there are selectors that are in your stylesheet that you are not using in your html files. I'm not a Topstyle expert so I don't know the details about how this works or what the scope of the search is (e.g. does it search all 'Project' files or just open files). I will try and post a screen shot here of how the interface looks when it does a search.
Hope that all makes sense.
Keep up the great work Karlis. Your software is just the best. And affordable.