I'm on my second CBB, first one developed an infection from which it never recovered, had him 2 1/2 yrs, my second one is doing really well, i have zero aiptasia in my display, which was one of the reasons for getting one in the first place.
When looking for one at your LFS make sure the mouth is undamaged, i've seen several with damaged mouths from shipping starve to death.
They are a beautiful fish, the only problem i ever had was with my first CBB taking a huge chunk out of a Blood shrimp i had, needless to say it finished off the $30 shrimp dinner before my eyes. 8O
HTH