This for me... As mentioned above, a measure of success is definitely more related to a reefers experience and goals. Maintaining consistant parameters and finally defeating the algae in my tank was my first measure of success. For me right now, watching my first few corals thrive is being successful. Down the road, maintaining large colonies might be my new measurement of success. So I would say where you are in your reefing journey will dictate what you feel is being successful which will be different for everyone.