I want to chime in on the defective screen possibility.
Living in FL, I take my Readers out all the time. It gets HOT and SUNNY here like 99.999% of the time
Anyway - I've never noticed any issues at the pool or the beach with either the 505 or the 700. The 505 may have appeared a little bit washed out in direct sunlight, but nothing to that extent. The 700 actually became more readable in the bright light
I have noticed though, that the screens seem to get better as they warm up. By that, I mean that the page turn and refreshes are very slow at first after a cold boot or waking it up from sleeping for more than a day or two. But after about 10 - 15 minutes of use it warms back up and speeds the process a bit. I've also noticed similar issues with battery life. When the battery is really low, my 700 experiences an effect similar to that. By that, I mean half the page disappears (literally) and it looks terrifying. A recharge and a restart usually fixes the problem