Indeed... By the time I saw this, this morning, I had already used it for detailing expenses and forwarding/filing away... Not to mention how great of a tool it is in common conversation when referencing items or trying to be detailed/descriptive, when not face to face with someone... Like you said, I believe it has me tied to it as well... I have often described the reason for my decision to be Note user, above other popular devices, as being due to the S-Pen and it's functionality first... There are indeed many reasons to love this device, but I just couldn't even imagine using a device as my only, or even my main device, without the S-Pen...
Edit - Just to note, (no pun intended), every time I grab my device (for the past 2-3 years, at least), the first thing that I do is draw/eject the S-Pen... The only exception might be when answering a call (even then, half the time the S-Pen comes out before the call has finished)...