After my initial feedback and having using Windows Live Writer more I have found a critical bug. I have not kept an eye on the groups to see if someone else has reported this (or if there is a work around), but I wanted to capture it here.
If you are modifying a post that was originally created with Live Writer and contains images which are uploaded to a FTP server, when you add another image and try and publish it then Live Writer will crash.
On the other hand, same scenario as above - except you are modifying the post without adding any new images - then it will be fine.
Hopefully there will be a new build fixing this as there is no work around other than manually editing the post directly on the site. I found this the hard way when updating the Call A Contact post .