I have been doing exactly that. It's not bad, much more suitable for startups than Legalzoom. But honestly I can see the potential for it to replace more than just standard incorporation. It could probably do most or all of an equity round, at least at the seed level where terms tend to be fairly standard (series seed/AA with protective provisions, etc.).

Not everyone wants to use notes, and not all investors are comfortable with them. This is particularly true of overseas investors who may not be comfortable with something "new" combined with the complexities of international law or their local tax codes.