The screen on the new 300 is just as good as the 505, IMO. I have owned both. The 300 screen is 5-inches diagonally and the 505 is 6-inches diagonally, otherwise they have the same 600 x 800 pixel resolution and the same crisp, easy-to-read type of screen.

I also own the new 600 because I thought I really needed the ability to highlight text and make bookmarks. However, I find that with having both the 300 and the 600 (I sold my 505) that my 600 mainly sits on my desk while the conveniently sized 300 is what I use almost exclusively. The 600 is a good reader, even though the screen is a bit difficult to read at times, but I think I will be sending it back. Otherwise it will become an expensive paperweight!