I'm not sure what program our district uses, but there are groups with differentiation. Yet, it's not enough for kids who learn quickly, eagerly and want something else new. In what I see, there is still a lot of review. Also, it has been interesting to see my ds in a group and how he fits in academically or strengths/ weaknesses. It has made it more clear that the "highest" group is not challenging at all. However, my ds is learning to cope (for good or bad- not sure yet). He does not complain or misbehave at school. He "races" ,as the teacher says, through he's required work with an acceptable level of neatness; so he can do something else like read. Then, he comes home and complains to me.
In saying this, a homeschool option may just be what's good for you! Keep us posted!