To read PDF technical documents is the main reason to buy PocketBook 902 or 903 (I want to replace the LCD with something very close to paper

). I tested a vizplex display (iRiver Story

) but form me the contrast is simply not satisfactory

. The font is too gray for me and the background is too dark comparing both with Kindle 3

. Do you have any ideea if PocketBook 902 has darker fonts, whiter background or better contrast comparing with iRiver Story ?
PS: I'm really very sensitive to the quality of display because my eyesight is poor