Well, one "advantage" for me is that it doesn't run Windows. :P

I never did use One Note, so I can't comment on the use of that.

HOW I USED TABLET PCS:
I used Journal Note extensively for tutoring, making math notes. I used the "handwrite into MSN chat windows" feature extensively for tutoring kids. I created pdfs of math problem sets and used the tablet to annotate solutions. I also would have my students writing on the tablet instead of paper as they solved their problems so that their work could be emailed to them (rather than get lost in bottom of their backpack) or so that I could edit the file so that the next student could work on the same questions. That's mostly how I used it at the time.

The dual screen wouldn't have been too much of a selling feature for that set up (an extra window to distract the kids!) as one, larger screen was best to replicate paper for them. But for how I use my eDGe now, as someone who doesn't work face-to-face and have others on my machine anymore, the eDGe is a actually a better set up.

MY MAIN USES OF THE EDGE:
- notepad replacement for non-permanent writing (comparing several flight itineraries before purchasing)
- keeping track of tasks/projects on the go in simple handwritten list form
- brainstorming ideas
- writing math problem solutions
- sketching floor plans, design ideas (we bought an older house and are slowly renovating)
- reading pdfs/ebooks; printing pdfs of web pages
- filling out pdf forms and signing documents by hand

1. The e-ink side doesn't run a complicated, bloated OS. So if I really do just need a notepad, I don't have to fight with Windows to simply handwrite. The edge may take just as long, if not longer, than a windows machine to boot up, but I also don't have to "click here for updates" all the friggin time to programs I have no intention of using in that working session. The edge never "wants my attention" or "needs my permission to continue." So for someone who pulls out the edge when I have a specific need to get crap out of my head and down on paper, or when I want to write out the dozen flight options I'm comparing, I like that it's a less demanding user experience.

2. The dual screens are insanely useful for taking notes while browsing. (I know you said other than the dual screen, but it's huge IMO.) Half of my time is browsing flight options, and not simple itineraries either. I routinely need to compare a large number of options spanning several handwritten pages. Sometimes I do this on my Macbook's browser, sitting on the table, while holding the edge to annotate. Sometimes I use the edge's own browser and have the e-ink side in landscape, flat on the table like where a laptop's keyboard would be. For me, the dual screen means not having to constantly bring different applications to the front, like on a tablet PC. Less productively, I can monitor my twitter stream or email on the LCD side while I'm working and never have to "click off" what I'm working on to check them. This is a major aspect of workflow.

3. Battery life is no where near excellent on Tablet PCs. The EE has the best battery of anything I've owned, and with a second one for swapping out that is thin, light and easy to have on me, I have never found myself without power.

4. The Journal app is pretty comparable to Windows Journal Note and to Xournal (on my Nokia tablet), so neither advantage nor disadvantage. It has the program I would use most often and it works well. Handwriting recognition of what I'd written was never a big deal for me (I don't think I used it much on the tablet PC), although both Tablet PCs and my Nokia allow you to input into any application via handwriting for when you don't want to use a keyboard. That would be nice on the EE, too, but not necessary. I also didn't have any more of a filing system than folders (didn't search using OCR or anything), so I find no difference in experience with search, file management etc.

5. Related to the dual screen thing, the "send to e-ink" feature of the native browser helps my workflow tremendously, as a lot of what I do is print web pages to pdf to save for later or to make notes on.

6. Not insignificantly, the edge is at most half the price of any comparable tablet PC options. So for people who already have a laptop and are not looking to replace it (especially Mac users, for example), the edge is the right combination of features and price compared to a tablet PC option. Not only might I have a difficult time justifying a second laptop (that won't be compatible in many ways with my current one), but when I'm traveling I don't want to have two full blown laptops if I can help it. So I can pay less, have the basic tablet features of a tablet PC (i.e. Journal Note) without a Windows environment and have a slightly smaller device with a better battery life. That was really how I looked at it, and why I didn't think twice about the price of the EE when I pre-ordered. Compared to buying a Tablet PC, if you're not making it your primary device, the edge makes way more sense all the way around.

So granted, I really use my edge more a fancy e-writer as opposed to an e-reader (which is why I think comparing with a tablet PC is very apt). This is why I'm keeping an eye on the devices mentioned in my signature: I don't need another "laptop" and I'm not likely to pay for one. As long as I have a writer that annotates and exports pdfs, i can probably be happy. I can easily see paying $200 for something that does that one feature well. From a consumer standpoint, it's not too much for a dedicated task, and I'm not "splurging" on something that duplicates functionality I already have in my laptop.

The edge, however, is a real workhorse, though and the dual screens allow me to do more than just that feature without getting in the way of that feature. (Both physically, by having another screen and OS-wise, having Android able to run apps but not affecting my work on the e-ink screen. I don't have to click to accept an Android update or click to acknowledge a program has crashed in order to clear the screen I'm working on.)

That's probably the best I'm able to compare the two devices given how I use(d) them.