I'm not sure I'd use something like this in my everyday work routine. The idea and concept are great, however to me this device is a bit cost prohibitive. It looks like their cheapest new pen runs around $120, while if you want anything more than the most basic functionality and storage capacity you can pretty quickly find yourself North of $200. At that point you're fairly close to tablet+stylus territory, which gives you note taking plus loads of other functionality.
I do see they have some "refurbished" pens for around $70, so that could definitely be an option.
Has anyone else used this device? Thoughts? Would love to hear from some others on the subject.