There was a recent discussion on this topic with more image comparisons in this thread link.
https://www.mobileread.com/forums/sho...d.php?t=156446
My opinion is that the T1 is the best of the 6 & 7" Sony models for readability. It is much improved from past models, and I am very pleased with it. I've had the 500, 505, 900 & 950. Text is darker, and I really like the font options. I have a K3 too, and it looks nice as well. However, I read more on my T1 than on my K3. If you visit the Kindle forums, several posters are upset with their K4's because they think the screen is not as nice as the K3. I think all that really matters is can you read comfortably on it and does it work for your eyes.