I think my 5 year old who is still in Nursery/preschool here in Norway has learnt a lot more than my other son (now 8) who started reception in London aged 4, when he was 5 and in year 1.
This is despite my other son enjoying benefits such as Karate, Mandarin Chinese, After school drama and Games workshop (read chess and noughts and crosses), along with Violin and Tennis. 
I think we are so eager for our children to learn, we push them so hard, keen for them to know everything in a short space of time. The result is often total overload, and very little actually sinks in, I think.
Of course children are different, but my youngest (who will start school here next August) has learnt so much about nature for weekly excursions, trips to the farm every spring and automn to see what happens with animals and crops, learnt about the seasons, changes, how we get our food, they have been foraging for berries and made jam, they have used the blueberries to paint pictures in "hues of blue", they celebrate UN day ever year, where they learn about children in other countries. Last year it was Nepal, this year it is India. They see films and learn about what the children eat, their schooling, etc.
My 8 year old London educated son had very little knowledge of the world and of science, at the age of 5. He could spell what he was required to, and not much more. And this is no slight on him, as he is well ahead of his yeargroup here, and on next years maths curriculum, and with a reading speed of 120 words per minute, in both english and norwegian.
We moved to Norway when my oldest was 6, and started year 1 here and it was like a fresh start for him. We struggled so in London, and he was so frustrated. For him, coping with mathematical concepts and reading at 4, was too young. I am blissfully happy with his schooling here. I am blissfully happy that my other son has such fantastic preschool education. When I tell nursery workers here that in London they dont go out if it rains, and if the rain stops, nursery workers run out with towels to wipe off the play equipment, they are speachless and think I am pulling their leg.
The downside is, we spend a lot of money on raingear, and on a really mucky day, you hose your kids down when you come to pick them up. It is great fun. Mums in high healed shoes cluthing their bags between their legs while manhandling a hose to clean off a thoroughly muddy child.
Thereafter, the go inside, and put the raingear into the heating cabinet (it looks like a huge fridge, but blows hot air from all directions) and get the kids change into normal clothing before leaving.
A full time place with 2 meals per day (you bring breakfast in a lunchbox) from 7.30 am til 4.30 pm cost just £250 per month.