Luke
I'm sorry that you Saturday was ruined, mine was to, flying all day. Just a few points:
The circuit height has been raised to 1000' agl from 800' in the last couple of years to reduce the impact of aircraft noise.
The airfield is the "gateway" to Marshall Aerospace and the company would find it hard to survive without an airfield. Due to the nature of activity that takes place at Cambridge the cost of maintaining the airport is very high, costs are reduced by trying to operate the airport commercially.
Close the airport, close Marshall Aerospace. Can the 4000 employees come and live in your house??
I am sorry that you have a problem with aircraft noise, have you spoken to the Airport Manager about it?