This is a device worth looking forward to. The one thing I hate about my iPad is that it doesn't have an active digitizer for note-taking. The S-Pen is a great reason to buy this, since it works quite well on the Galaxy Note.
I'm using the Bamboo stylus and it works pretty well. However, Apple built their touch interfaces for fingers from the ground up. The active digitizers allow for significantly more accurate touch input with a coordinating stylus, which would be ideal for notes.
My friend has the Eee Slate, and his notes look about 200-300% cleaner since it has a (Wacom, I believe) digitizer. Mine are all scribble thanks to the stupid chubby rubber tips.
IMHO, it s not very convenient to write on a vertical surface unless it is on the same level with your eyes... so i m not sure why All-in-One PC needs the pen.. most people sit at their desks and the monitor is lower and farther away ....