We've had our kid in there for 2 years. Its good. If our somewhat developmentally challenged 2nd kid can get caught up by K we'll put him in as well.
Class times are great because it really allows you to either A) get school home work or projects knocked out before it gets late into the evening or B) allows you to put em in activities without it getting to be too much or C) a combination of both A & B.
Class sizes are very small so each child gets lots of attention.
A&M Consol's Valedictorian from a few yrs ago did KOR through middle school I believe and from my own personal perspective laying a foundation like that of KOR or any good private school and then transitioning to public school in Jr High or High School is a very good formula. (Again just my opinion).