In the Uk it is still the sangat that has the final say in any committee decisions.
However as anyone who lives in the UK will know that politics is always a big issue. Some gurdwaras have string committies and fill the gurdwara with there followers when important decisions are to be made on how the gurdwara is to be run. Other gurdwaras (particularly the smaller ones) are controlled very democratically.
Committies are chosen by the sangat, and decisions are made by the sangat.