I'll stick with the 505.
Touch-screen not really useful, I hate fingerprints on my screen. And using the stylus is cumbersome. If you really want annotation capability and more software choices (not just books), the Iliad is the way to go.
Thumb swipe -
You will have a smeared and scratched screen quite soon. No way.
The light is no big deal, it just kills your battery sooner. Easier and cheaper to light it with a normal book-light.
Nice looking device, but I would not even consider it if it was cheaper than the 505.