Depends on the schools, depends on the kids, depends on the parents.
There, thats helpful eh
Nearly all the kids at dd's pre-school are going to private primaries. dd is not, and the state primary we've chosen is undersubscribed. But its by far the most caring of the schools we visited (private and state), smaller classes than all but one other, and has excellent values as well as very good SATS.
If the local primaries had been awful when we looked around, and we could afford private (which we can) she would not be going there. But I'm very happy to say she is.
My neice and nephew were state educated throughout, and one went to Oxford (now doing her PhD) and the other to Bristol. I went to private primary and secondary and messed everything up, more or less.
There just aren't any black/white answers!