Productive, convenient, efficient. The Moleskine pen is a thing that has improved my project and personal work process. Possibly, most likely, extremely biased review, as I have never used anything like it – besides a tablet. You can use it offline (disconnected from Bluetooth), you can email the document at stages of editing, and you can also edit the document through the app for such things as transcribing your text.
Whether it is a doodle or a part to a project for a client, this is one of the most reliable things I use and it gets the job done. It takes the time out of having to scan a sketchbook or paper when you are not able to, which is great when you do not have immediate access to such things.
That part about editing, however, is limited as you can not change hex colours by a direct input of the code. But you can use the colour wheel to guess and/or see different versions of colours. I also left it off for a few days and the battery seemed to drain a lot more than I would have thought.
As always, these things are not cheap but if you are willing to make that investment, this is something that is worth the money. Making my purchase, I bought the set with an extra notepad just to keep me going.