To be honest I didn't realise that there was such disparity in circuits. I'm sure local factors at airfields mean they have to be tailored to suit but is there no CAA equivalent of a CFS - a standards unit that examines instructors?
p.s. I have also seen aircraft that fly circuits about 30miles wide! Especially one guy who flew downwind and did a 4 mile final, causing a knock on for everyone else behind him.