I feel like current 8th graders will be the experiment. We moved from VA to CA when oldest DD was starting 6th grade. Our CA school district (small and among highest rated in state) did not implement common core for her grade level at all in 6th...it finally started implementing CC 6, 7,8 when she was in 7th so her grade was still on 'old system', i.e. they didn't have CC 7 or CC* ready for her class, so the kids kept forward on the old track...so, she had algebra in 7th...changed schools for 8th and is currently in geometry there. It's clear that the private schools in my area definitely discourage the 'push ahead' in math, and most are teaching Alg 1 over grades 7-8. However...when I have conversations with friends in VA, there seems to be NO change in math there. Still algebra as the standard for majority of 8th graders. If anything, I am hearing about more specialization for mathy kids - Alg. II in public school for 8th graders! Note, VA is not a common core state. I hate to be so skeptical of CC, but...I could write a book on how easy my daughter will say middle school is at what is considered a strong CA public school vs. her elementary public school in VA. And she's not profoundly gifted, just your average smart kid!