We accelerated from 4th to 6th and did not regret it one bit. Life for my DD was becoming miserable. However, even that was not enough. So, we just brought her home to homeschool and even though we are working well beyond the grade level, we actually officially rolled back the acceleration (figuring we can reinstate it if we wanted.) If she were going to stay in school, we were going to insist on another year acceleration.