Pity about iRex - I still like my DR1000S for reading PDFs and annotating, although you have to use the stylus.
LCD aside, the iPad is one of the easiest to use for reading PDFs and annotating (many different app choices for that - GoodReader, etc.). Pity you want only eInk, although the iPad display is very easy on the eyes.
The PB902 looks pretty good - again it is a stylus touch screen, so even though I'm sure it's improved on the DR1000 for response, ease of use, etc, it still can't compete with the iPad-type touch-screen interface that is so convenient to use.
Best of luck, and if you do get a PB902 I'd be interested in your thoughts on using it.
