My granddaughter attends a home school support school that has a lot in common with what they're doing in Finland. The students are split into age groups of about three years, rather than one year grades. If needed they move back and forth between age groups so that they recieve instruction appropriate to their level of need. The school does not give grades (in the sense of ratings) at all. Students work on something until they have it mastered. They learn priciples and techniques, not factoids.
In the three years we've been there every one of their graduates has been accepted at their college of choice (plus almost everywhere else they appplied). They've averaged about 100k in merit scholarships.
Best quote from a former student "The Attic taught me to love learning and to be responsible for my own learning."
http://www.the-attic.org/