They are easy to keep. They just can get mean. They need room and food. 180 at least and fed 3-4 times a day. They are like people... meet their needs and they are reasonable. Overstimulate, undernourish and cram them into small places, and they act like some a holes on a reality TV show. Most reefers put them in too small of a tank and then will not feed them enough to keep the nutrients down on their reef.
I have had several in my 240 and they do well until they reach about 6", which can be done in less than a year if you are feeding them correctly enough to keep them nice. Then, they move on to the 7500G display at a local restaurant where both of them are still alive.