I have 3 kids at the school and it is fantastic. Our oldest attended another private school in town (which I will not name) and KOR is head-and-shoulders above it academically and especially in the culture.
The families are very involved and the school sees itself as an extension of the parents' being the primary teachers, not the other way around. So, family involvement is paramount. Thus, you get a lot of good people helping.
Academically the 2 kids who are academically-oriented are challenged and the 3rd, who is more artistic, is also pushed, but not left behind. They are several grade levels above other schools, esp. in math.
They have cross-country, band, basketball, volleyball, etc. There are now 2 campuses and the school has such a good rep that most classes have waiting lists.
Did I mention it is much cheaper than other private schools?
I couldn't recommend it higher and I was a doubter going into it but have been won over.