Too long AND very hard? Tell your kid that the "average" kid won't be able to understand the test and do the whole thing in the time allotted? (This is from the PARCC test but I wonder how different the SBAC is/)
How does that really help a student and how do you think your child would feel? I know my sons liked a challenge but I also know that they both would have rushed to finish, maybe even guessing answers because they would not have wanted to be thought of as "average."