Kindle 3 is much better than PRS300. PRS300 uses older display and I can tell you from first hand experience that going from prs-350 which is new generation of displays to prs-300 was horrible for me

. Funny thing is that I used PRS300 before but after using 350 i wouldn't go back. 300 is very slow and screen is much worse then on 350/kindle 3
But then again for $40 I guess i could use it