one primary reason for me and my friends whom works in the IT industry to get a E-paper reader is because after 20 years looking at various generations of Monitors / LCDs, our eyes starting to develop issues. For us whom has a lot of documents on electronic form and got customed to read stuff on computer screen. E-readers are a good way to protect our eyes. It indeed generate far less stress for the large number of us. So, the health benefit justify the price to be paid on this reason alone.
Ereader's next must have is to display colour and to be able to double as websurfing device, so for the likes of us, would further use it to protect our eyes.