Somehow Tortuga's post is prior to mine, but didn't actually show up on the board until later. Tortuga, you did a good job of stating what I was trying to say.
As for the Math and English ACT scores meaning more - some schools use only those two sections. I know that is what Pitt did when my eldest applied there (and that actually helped her to receive some merit aid). I don't really understand it, since I would think that Reading (comprehension) would be more important than grammar. It seems that comprehension is more important on the SAT - many schools only look at CR+M, or give less weight to Writing.
As for when to take the SAT - my kids did that in 7th grade. We are in an "SAT area" so we didn't even consider the ACT. One reason I might hesitate to use the ACT for a younger kid is that the pre-HS scores do not get wiped off of their account. With the SAT, scores for pre-HS kids get wiped away in June or July unless you make a specific request to keep the score.
