I think the place that I read that 10 IQ point statistic is in Dr Ruf's 5 levels book. (I think I've heard her say it during one of her presentations also). I can't find my copy right now to check to be sure.
ultramarina - I totally agree with you about not underestimating my second child. That is why I wrote the post. (Maybe I just needed to hear someone say that my two kids can both be gifted but in different ways). My first experience with a gifted child is the one I've had with my first son. As I stated before, he is an overachieving perfectionist. My second son is just so much different from him, but still very bright.