I have used Live Writer for a few posts and I quite like it. The editor is better than editing the blog directly and it has a few features that are really useful.
Managing categories is much simpler and the list to select a category is sorted alphabetically which is really useful. It can also be set to prompt to add a category and tags before publication which is useful.
Being able to save to the blog as a draft is useful as it gives another chance to check it over before publication. The spell checker is a wonderful addition
All I need now is a reminder to use it 🙂