I completed both courses recently and both very well run by the instructors.
RSO was 2 days with mornings in the classroom and afternoons on the range at Melville running squads of shooters, so some good practice in running a range. Included comprehensive notes. Suitable for running club ranges and would recommend.
RCO was focused on MOD ranges. All classroom and theory based but still had a great opportunity to ask questions and engage in discussions. Included latest edition of RCO handbook. There are exams!
RCO quail lasts 6 years!
Cheers Jon