It says it is WYSIWYG, but its not really. You have to add the html tags manually to get things like headings, lists and other stuff. When you do this, the formatting gets all strange with double line breaks, so to make it look right on your blog, you end up writing a block of text, with tags, without any line breaks.
There is a button to add formatting elements, but this just puts the tags around the highlighted text, it doesnt make it actually appear formatted.
I had high hopes for an off-line, visual editor for my blog. myWPEdit did not fulfill those hopes.