I have bought a total of 6 of these pens, because I teach at an MBA program (top 25, so not too shabby a school) and am trying out different technologies with the students to see what they like, and what works.
Pros - inexpensive, easy to use.
It does a very good job of clipping to the top of a spiral notebook, turn it on, and take notes. When you get home, plug the receiver into a PC, and your notes are now in digital form.
There are software packages available that convert the handwriting into machine readable characters, but so far, the APen software itself does not convert it into a document which is editable into, say, Microsoft Office Word.
It is not particularly effective as a bamboo tablet alternative for me & student guineapigs. You can use it as a “mouse”, but it tends to be a bit sloppy.
So, it gets really high scores for doing basically what a scanner would do, but without having to run the pages through a scanner. And, since a shocking number of students seem to have scanners which break, or only output GIF files, this is a pretty easy solution for that. I also like it better than a stylus on and IPad, since the stylus is relatively crude in its sensors, and can be upset by an errant finger or palm resting on the screen.
I like it better than the lightscribe, since it works on any paper, not expensive dotty paper.
Overall, pretty good at a limited number of tasks, and for the price, it is great.