I think 'massive' is the right word to describe the gap that is already widening between the children that are hot housed in and out of school throughout the year.
I can see why it might sound like an exaggeration, but I'm struggling against the weight of a system that is rigged against my son from the start. And I'm too ill to move the mountains necessary to get it sorted out for DS.
Approx 1/2 DS class are tutored or go to extra classes outside school. The school is achingly middle class and in a very affluent catchment area, where the school has raised millions for new buildings / technology/ teaching kitchens, school kitchens and chefs etc. There is a culture of mothers who don't need to work being a very strong presence of parents at the school, which is great when used as a resource for everyone, but less great when it's used as a way to keep on top of their own children's progress and push them forwards all the time.
Last year there was great teaching and a strong willed and just, good, teacher & TA.
This year has been terrible, with a very inexperienced teacher who only registers loud extraversion as intelligence & effort, and only reacts to equally loud bad behaviour as worthy of needing extra help or attention... Well my poor little quiet boy without confidence just got ignored for the past year. And he has a single working disabled mother which has been a significant disadvantage to him this past year 
I was already on this thread as I was trying to decide how to catch DS up from an awful year at school, only to find this ridiculous amount and type of homework today in the depths of DS school bag. It will ensure he enters next years schooling without that gap having been closed, against all my efforts.
It makes me feel very very sad.