An update for you all.
I bought a PRS 350, after spending 30 minutes playing with it in store. I wanted to ensure it was an 'upgrade' from my 505.
It's brilliant. It's a great deal faster (this is mostly a user experience thing rather than benchmarks) indexing and page turning. the screen is lovely.
and the page turning? just the merest swipe is needed, so I am very happy.
ps, and thanks for not thinking i am loopy!