I loved junior school. I missed a lot of primary and only have a few scattered memories of it.. The last remaining junior school on the other side of town has officially merged with its infants to become a primary.
The more I ponder it the more I think primaries are not overly a good idea given that many junior schools either shared sports facilities with their infant next door neighbours or had superior facilities. Neither is year 7 in secondary a good idea. Another year in a junior school separated from KS1 and foundation will allow them to alternatively play at being grown up and still allow them another year to be children. Junior school in my area covered 7-12years.
I think Gove could replace his free school idealism with re establishing junior schools.