My state did a lot of chest bashing and teeth gnashing over Common Core that, once you peeled back the layers of bad terminology and silly posturing, turned out to be based on some reasonable objections regarding implementation, rather than the standards themselves, and one of those objections was PARCC. The state has continued with adoption of CCSS, but PARCC has been postponed indefinitely.
On the other hand, when we were homeschooling our DD9, we were under no obligation to take state assessments, but we opted in for the state test, which she could still take at the public school for free, and we paid for the SB10 as well. They made for highly valuable data points.
