I went to a comprehensive and it was hard. I was bullied, no one encouraged me and although I came out with a few exams, I could have done so much better at the local Grammar. However, it wasn't an option for me, my parents had never gone on to further education, so it was never going to happen.
DD went to the local state school until we moved her in September (y2), to an Indpendent school. We thought she would do well at the local school, but as time went on, it was obvious the class sizes were too big, she wasn't very happy and was beginning to switch off to learning. This was an Outstanding School by the way.
She is now thriving, loves the new school and is keen to learn and be involved, we have a different child and I am so relieved.
As Whippet says, it depends on the child and their needs as parents we have to look at the child and think of what is right for them, not what we want for ourselves. If our dd had been very self motivated and was extremely bright, I have no doubt she would have done well at the State school, as it is, she needs that extra input from the teacher and less distractions from a class of 30 and she is getting that in her class of 16.
However, you don't know how your child will respond to school and what type of student they will be until they start, so it is extremely difficult to make an informed decision, therefore we are bound to look at our own experiences.