I used MCT island level w/ my 4th grade and 1st grader. I thought my 1st grader would be just on the fringe, but he was so taken w/ MCT that he fully immersed himself in grammar. He has retained everything and loves it. He hasn't done all of the writing but I'll come back to it in the Fall with him. FOr writing, I do Writing With Ease so he does copywork followed by dictation. In the Fall, we'll move to Town level. I expect for my 1st grader, we'll be doing an MCT level every other year.