As one who is in the education profession, AND one who had their child enrolled there for (much longer than I should have) over two years, I want to address why I believe Century school is an academic farce. One of the glaring mistakes they have made is to rely solely on the WJ assessment. This test will (barely) measure your child's reading skills, but any single sub test or group of tests using the WJ will only give you accurate measurement of ability under the very best of conditions.
This test is ok, but only if the school also uses another supplemental test, such as the Grey Oral Reading to measure rate and accuracy under timed conditions and the Test of Word Reading Efficiency that measures word attack and sight word reading under timed conditions. They should also tell you what level text your child is reading independently and on an instructional level, using some sort of standard measure such as Fontis & Pinnel, DRA, Lexile etc.
As far as the parent who is unhappy about the math assesment, this is completely understandable because the math subset of the WJ is extremely lacking. There are quite a number of other math assessments that are much better at measuring necessary math skills and their components such as working memory, perceptual reasoning, visual spatial acuity, etc. My child needed more intervention in several areas (we later found out in more comprehensive assessments done once she reached public school) and Century did not meet up to those needs. Regarding the parents who are thrilled, that is good. But their children were likely very high functioning in the first place and so had the self-impetus to continue growing in that environment. I also did not understand why their parental surveys they hand out a couple times of year, always asked the same questions, and whenever I responded with less than favorable reviews, I never received one phone call or inquiry as to why. Why bother if the responses that are unfavorable are just ignored? Socialization can be attained just as well in a public school setting, without paying $500/mo. or more. Century needs to do a lot better for what it charges. Beware of unaccredited schools!