I considered textbundle, but went for HTML for one reason: data accessibility. Imagine in 20 years from now you'd want to access your data and do not have the app around for some reason. You would need to find another app that supports the .textbundle format. Or you would need to manually rename all .textbundle notes to .zip to extract them. Even if a normal user would know about this, it would still be a pain. With HTML you can drag a note into a browser and see the contents. Links to other notes will work as well. Images will show right away, too. Pros and cons for each format...