FireRunner--The viewability on the Sony 505 is superior to viewability of their newer models. In my opinion, the 505 has one of the best e-ink displays around. The newer models added a touch screen at the cost of clarity.
My husband has a 700 and a 900 and my 505 beats them hands down. I've compared my 505 to both a nook and a kindle and personally find all three to be similar in regards to viewability.
dordale