I like that it's easy to use, has many options (like search) which are intuitively organized in folders.
It also allows you to save your work as HTML or PDF documents; this feature alone makes me keep using it! The interface could be improved by adding more icons/buttons - there should be at least two rows of them instead of one row only with some space left over. If you're looking for an office tool to organize small projects, then MousePad will do just fine! You can edit texts directly from webpages without downloading any third-party software.