I doubt that you know this already, but I have a recently moved schools. I was unhappy with the school that I was attending during my GCSE years and decided the best decision for me was to move schools for sixth form. In an attempt to be as helpful as possible, I thought it might be a good idea to share the story of this: my fears, my reasons, the successes and drawbacks of the whole ordeal and hopefully I'll be able to give some invaluable advice to those who may be in the same dilemma that I was in year 11.
Secondary School
From years 7 to 11, I was attending an all girl grammar school which, up until about year 9, was an environment that I flourished in. I was quite honestly, a nerdy student; I did all of the work and tried my best in order to get consistently high grades. As I went to a grammar school, the majority of people around me were high-flyers; they gained good grades and worked as equally hard as me to achieve their best, however as a result of this, school became a very competitive environment. With grades being fairly even between everyone in my year, there was a much more significant focus on your other skills and personality traits and as you can imagine with it being an all girl school, it became quite catty, (which is a nice way of phrasing it,) quite quickly. This was not at all an environment that I flourished in.
Reasons For Moving
Second to the unpleasant environment that developed in the later years of my time at the school, I found that the school had little respect or concern for the pupils that attended that school but instead solely focused on the grades we would achieve in our GCSE exams as it would therefore reflect well on the school. Resultantly, the school was unfocused on the wellbeing of the students or their learning experience. For example, I had a completely terrible time when it came to studying physics. I had 4 different physics teachers in year 11 alone. One thought our lessons was a time for joking around, another quit within 2 weeks of being in the school, one was a supply teacher who didn't teach physics at all and the other had recently moved from another country and didn't speak particularly fluent English, (he once called toes, the fingers of our feet!) which made it extremely hard learn and he also gave up very quickly, storming out of the classroom when our class failed to cooperate. Although I am aware of multiple pupils and parents, including myself, who complained about our teachers, absolutely nothing changed. Although I originally started off with an interest in physics, this quickly went downhill when it practically became a self-taught subject. Although I hope this isn't a reason for many others, it was a reason for my leaving.