My Sony PRS-950 has been really good. It's the larger of the Sonys at present. Like Aramis, I'm waiting for the full page display size version. It won't replace my 950, but I'll use both.
The non-emissive display has been great for me. I have been using various LCD screens for readers ever since my eyes made me move on from using my HP 200LX for reading ebooks. I was never able to read a novel straight through with any of them, I found myself reading in short chunks, taking breaks for my eyes or just having my attention wander because my eyes weren't comfortable any more.
With the Sony, I've read entire 40-50K word novels through at a single go, and in one case started a sequel without a break. I'm reading 2-3x as much as I used to since I got this. It's started to get so that I look at a lot of my books and wish I had them in e-form since the Sony Reader is lighter and easier to handle than a book (hardbacks, anyway, and paperbacks with tight bindings and small gutter margins.)
I read the LBBs from the CT CD in portrait mode. It's so close to original size I can't tell the difference. I read the JTAS the same way, comfortably, though sub-sized.
I'm really looking forward to the full tablet size version, though. Technical materials will be far easier to read in that format. But for everyday reading, and for something more portable, I'll still have the 950.