I also agree with lucounu. No offense to La Texican, but her method would have turned off both my kids, or at least made them suspicious.
I am obviously working with a sample size of two here, but my experience with having a child who started reading at just-4 and one who started reading at just-5 has been that the younger child has much less stamina. He is decoding very well, but tires quickly and lacks the attention span that DD had when reading clicked for her. I am just now seeing him read a whole picture book at a time (aside from very easy early readers; I'm talking about a real picture book), though if you tested his actual ability and fluency he would probably be at about an early 2nd grade level. Still, he is a pretty different animal than a typical late first-grader reading at a grade level, you know?
