The advantages of WYSIWYG editor are:

• You see directly the result
• First web pages created within hours
• Easy to control bigger web sites
• Easy to use advanced HTML: DHTML and integration of Java applets or Flash
• FTP software included to publish web site

Disadvantages:

• You need a few days to get used to the interface
• Software needed to create web sites vs. text editors are on every computer for free