Our district adopted CC but thankfully chose to pass on the combined Algebra/Geometry sequences. I think it would be nearly impossible for late acceleration under that model.
Both arguments for and against late acceleration(7th & later) have merits for different reasons. On the one hand, it is far more practical to accelerate in elementary before you hit Algebra I. You really want every concept/procedure from Algebra I onward to be completely solid rather than "easy come easy go" so I would personally hesitate about "skipping" from Algebra I onward. On the other hand, many kids sail through elementary math and even Pre-Algebra but their advance ability or lack thereof only become apparent after they tackle Algebra. In that sense, it is logical to wait until they get to a level that actually measures more advance abilities before accelerating. Having said all this, these analyses don't necessary apply to "gifted" students BUT keep in mind that the accelerated tracks tend to be rather inclusive and aren't normally reserved for technically "gifted" students. Oftentimes, you have to come up with guidelines that fit the top 25% (or more) rather than the top 2%.
