My DD was in a primary school nursery last year - 25 children, 1 qualified teacher, 2 TAs and floating students on placements.
All of the children coped fine with a full school day, none of them were forced to do anything academic. It was very similar to the private nursery where she was the year before except she wore school uniform and it was free. She then went on to the private nursery until 6pm.
The amount of rubbish people spout about children being deprived of being children etc really annoys me. In many areas - such as Central London where I live - both parents need to work and so rely on nurseries, childminders etc from 8-6.
Frankly most children have a wonderful time - we live in a tiny flat with no outside space, at both nurseries she was socialising with other children all day, running around outside, doing fun art projects and so on. What isn't great about that? Then we spent quality time doing things with her at the weekend.
For children from very deprived backgrounds where they may have multiple siblings, no money, parents without the means to provide a stimulating environment - whether that be due to finances, disabilities, social issues like drug/alcohol abuse etc - what's not to like about the idea? Far better that they are spending the day with responsible adults having fun that being shoved in front of the TV with a bag of crisps.
It will also make it much easier for women to return to work and for families to not have to make the huge sacrifices to pay for the uber-expensive childcare in the early years.
Before they did away with CB for so many people, I always thought it would be better to scrap it entirely and just provide free childcare from 2-4 instead.
FWIW, unless a school is VA, being in the nursery makes zero difference to whether you get a primary place or not.