Our family has had a great experience with The Academy, which I think is a remarkable school. Our two older kids went there before moving on to senior school, and our youngest is there still.
Things I like about it:
First and foremost, our kids had a fantastic time there. They made great friendships (sometimes across year groups, as the classes are small) and really enjoyed their time in school. The place is very informal and non-institutional. Some might call it chaotic, but I see it as an environment that allows freedom and spontaneity.
Second, our kids all received an excellent academic education. The school isn't selective and has children with a broad mix of abilities, which it caters to remarkably well. It isn't the sort of academic hot house which aims to send all kids to St Pauls or Westminster regardless of natural ability. Rather, it caters to the aptitude of the children, and allows them to achieve their own full potential. For sure, the children with the capability to do so are given the preparation to go on to the very best secondary schools, as many do every year.
The main asset of the school is the passion of the teachers. It may not have the facilities of a larger institution the buildings full of high-tech gadgetry and so on but the teachers here have the passion and ability to connect with their students at a personal level, which in my mind is all that really counts.
I'll admit that it's a distinctive, even quirky place, and certainly isn't right for everyone. If you want structure, discipline and respect for authority, best look elsewhere. Likewise if you want someplace that will promise to get your little darling into the top school of your choice regardless of native ability. But if you're looking for a unique environment in which children can be themselves, be happy and flourish academically, then it's worth checking out.