I used the very first build of this on a Live Spaces blog (back when it was still MSN spaces), and kept it up to date. It's really come a long way. It's very small and stable., and the plugin API is easy to code against in .NET. For quality, this is one of the best blog editors I've used, and I've tried many. It's not just for Live Spaces either; some of its best features are for non-spaces blogs, actually, as evidenced by some of the better plugins not working for Live Spaces.