I think most of the complaints against the 900's screen are from people with little or no intuition or imagination. They look at the screen under one lighting condition and judge the 900. NO e-ink screen looks good in low light. Few, if any, look good in the flourescent lighting of department stores. However, if you read in direct sunlight, the screen on the 900 looks fabulous. If you use a good book light for low light reading and position that light appropriately, the 900 screen looks fabulous.
And do NOT look at a 600 screen and think the 900 looks the same. The 900 screen is MUCH better than that of the 600. Unfortunately, many Best Buys have 600 models on display but no 900 models on display.