A final addedum. One of the drivers for me in getting the PRS-700 over a PRS-505 would have been note taking.
On reflection this is on my behalf self dillusional. I find typing anything more than a word or two on a slow to respond on-screen keyboard impossibly frustrating.
Instead on my 505 I carry a shorthand pad and pencil! I can bookmark the page I want to make notes on. Then scribble to my hearts content in my pad!
If I need to write loads, then I simply unpack my laptop and use the keyboard on that!