One of the weaknesses of the default WordPress Visual Editor is that it lacks some features.  It often happens that a client is used to a particular visual editor and when moving onto WordPress he begins to dislike minor features which he could do before. Some of the main things are changing the font-size , and inserting a table from the visual editor.  

These issues can be easily be resolved by adding the TinyMCE Advanced WordPress Plugin – http://wordpress.org/extend/plugins/tinymce-advanced/. Which can be installed and configured in a few minutes.  You only need to drag and drop the features missing in your current editor, such as the font-size and table for example to include them.