Early today I purchased a Sony Prs-300. Knowing I would be spending all day at the hospital (my Mom had surgery today, she is doing well!) I thought it would be a perfect time to see if the smaller screen would be doable for me for reading. mike_bike_kite is right, the device itself became transparent as I got lost in the 'book' I was reading. Page turns were quick enough and I was able to really enjoy reading on the 300. I like the 300 a lot and while I would enjoy a bigger screen the small size of the 300 does offer some advantages regarding portability.
I see another problem on the horizon though. After spending a lot of time reading about, thinking about, looking at and trying out various eReaders I find that I think I could also want more than one of these things! For example, take the Sony Prs-300 and also the 505, they have an "industrial" type look and feel to them I think because of the metal housing which I really like. The nook would be nice to have also, it has a bigger clear screen, excellent store and local store here in my town which I could take advantage of with the nook and the local deals. The Kindle 3 is said to be coming out possibly as soon as August?! What will that be like...?! It seems like the perfect marriage of my love for reading and my love for gadgets and technology. Help!