I use both. Metro version primarily on my SP3 and the desktop version on my desktop system. Like kittengirl says, the Metro version is slightly better at the note taking side on the SP3, and since I can sync OneNote across devices, I can open any notes I took on my desktop and do some more powerful editing on them if need be. I use OneNote for multiple purposes (i.e. grocery list, note taking, journal, and my daughter's school work), I find that kind of work flow is what works best for me. The metro and desktop versions were designed to compliment each other rather than compete against each other.