I just don't think school (or at least the conventional, what passes for education in the state environment) works very well for very bright kids.
Ds1 in particular has totally lost interest in learning (or rather he has had every ounce of interest in learning quashed by teachers). For example - learning about instruments that measure the weather: ds1 was sooooooo excited. He came home and wanted to design and make each instrument, a working machine. He asked his sister if he could have a single piece of her long blonde hair, as he had read and wanted to find out if it was true that blonde hair worked better than other colours for measuring humidity etc etc.
His homework was to google which country x instrument was made in, what year y instrument was invented, and which scientist invented such and such z. He then had to draw or make one of them, but it didn't have to work. Just a copy. With labels.
He wanted to make all of them - but then got so fed up with trying to find out what year blah blah blah was invented and where, that he ended up hating everything to do with it. And of course, we weren't helping, be a sue we were trying to get this to do his boring and completely pointless (except as a lame research exercise) 'science' homework.
They then had another science project, and were sent home with a list of electrical components and had to design a steerable remote control car. (We were given a shopping list for the components, and duly ordered the bits he needed). When the stuff was delivered to the school, he was given a one sheet 'how to make a car' rubric, which they were not allowed to deviate from (the simplest possible design with a single steerable axle etc) He was gutted that he wasn't allowed to make the car he had designed himself and ordered the pieces for - he had been looking forward to the pieces arriving so he could get on with it. The spare bits were sent home in a bag at the end of term, by which point he had completely lost interest because the project at school was over and he hadn't been allowed to follow through. (I was also mildly pissed at the waste of money). I mentioned his disappointment in passing to the teacher at the next parents evening, and she basically said 'god, no, they are only allowed to follow the rubric. We don't even let them design a body now, as they were coming up with all sorts, so we have taken that out of the program'. The teacher was so openly adamant that any deviation at all from the bare bones of the curriculum was not in any way accepted or desirable, that the kids have no chance to experiment or actually find out things on their own.
It was a shocking example of exactly what sort of deviations from low average are acceptable in a classroom. None.
Getting tests done is interesting, but doesn't make the blindest bit of difference in my experience. The psych suggested they look at him skipping a year. The school read the report, digested it (allegedly) and then put him in a mixed year class with the year group below.
My girls are a different kettle of fish. One just does all her homework at school in the lessons, so even at 13 hasn't had to do any homework. Even she, by last year, was just essentially whizzing through it because she didn't really have to learn anything - it was just ploughing through, there's no extension involved. Just churn out what's expected and wander off.
The little one has other issues as well. Their way of differentiating was not to give her any math classes for a year, because she knew it all, so was allowed to read or write a story instead. No, I didn't know this at the time.
I'd homeschool if I could afford it. I get flashes of absolute brilliance from all of them - and they get hooked on something and want to keep devouring it, making stuff, learning, but I have to make them sit down and do some pointless worksheet instead, because it's their homework and even though I know they know it (and so does the teacher) the most important part of their education is to churn it all out again and hand it in tomorrow like everyone else.
And don't even start me on spelling lists that are misspelled.
I feel sorry that teaching has become such a dumbed down by rote hideous experience. And that goes for the teachers too, not just the kids.