Just to follow up on this post...
I went for the m92 and have been using it for the past two months. It is much buggier than the EE, but has some enough advantages that I've been using it as my primary academic reading device.
Here are my favorite features:
1. Absolutely above all, the pearl eink screen with the increased contrast is a pleasure to read on. I'm sure you've all seen them. The Edge screen is great, the pearl screen of the m92 is even better.
2. Annotations: it has a couple of features I really like, including the option to export all of the text you've highlighted into a text file. The text file separates the text chunks and includes the page they were extracted from. Very handy and the export works quickly. The highlighting feature also works better - more precisely than the EE. However, it does not have line straightening, one of my favorite EE text marking features. My lines are back to being messy.
3. Performance: it's a bit speedier than the eink side of the EE (as it should be considering how much newer it is).
4. Syncing: not as good as the EE by a long shot, but I've found it very easy to use an app to sync the files using and app that copies things between the SD card and the indicated folder on my computer. I don't miss the dropbox connectivity as much as I had expected. (This feature is said to be in the works though)
5. Related to number one (my second favorite feature) GLYPH EMBOLDEN in PDFs!!! If you have a faint PDF, this feature saves it and makes it readable again! Even with good PDFs I usually punch this up a bit for increased contrast.
The main thing that this device really fails on is in note taking. It has all of the potential in terms of hardware (the stylus is more precise than the ED), but the note application is not very good right now. I only use it in a pinch. This may be improved though since the developer community is strong. In addition to a few annoying bugs, I have a couple of other small issues (ex. the color of the highlight when you flatten an annotated PDF and read it on your computer is best described as 'mud,' both ugly and hard to read - but on the upside, you can edit the highlights on the exported version and it maintains the searchability of OCRed text - something the EE falls short on).
Overall, I've been very happy with the m92 and would recommend it to any Edge lover who uses it primarily for reading and academic text marking.
Hope this is useful info!