WYSIWYG or What you see is what you get - it sure sounds good. Visual WYSIWYG editors are a useful tool. The allow visual WYSIWYG is nominally true if you are the only one viewing your Web page. But creating a Web page in a WYSIWYG editor does not relieve you of your duty to test in multiple browsers and operating systems if you're planning on showing it to anyone else.
One of the most frustrating situations I had was building a page in Dreamweaver. Now this is arguably the best WYSIWYG editor available, but when I built it in WYSIWYG mode the page looked great. Everything lined up perfectly, and was exactly what I wanted. Then when I uploaded the page and tested it in IE and Firefox, it blew up. The layout was messed up with things overlapping and not floating correctly. It was a nightmare.
What was especially interesting is that Dreamweaver allows you to view the pages in the Web browsers as well as in the WYSIWYG viewer. I did that and they looked great there too. The problem happened when the page was uploaded to the server. But it's not just the server that can affect your pages.
Just because it looks great in your WYSIWYG editor doesn't mean it will look great when it's viewed in another browser. Designers that use WYSIWYG editors on Windows often have problems when their pages are viewed on a Macs intosh or Linux system.
WYSIWYG Editors Are a Tool
Use WYSIWYG editors as a tool, but not as your only judge of whether a