I managed a LFS and we always ordered cleaner wrasses. Through my experience, they are a very sweet fish. Within minutes of them going into holding tanks, they do this little dance, which I always assumed was the "please don't eat me" dance.
I never had one in my tank, but friends of mine do and they've carried that sweet personality with them.
That being said, just my observations, they don't tend to be long-lived in the home aquarium. I know some people have them for a few years, but eating always seems to be the problem. They either A) Won't accept food and slowly fade away, or B) Eat food like pigs but still lose weight and fade away.
Other than that I have nothing but good things to say about them. I had one that when I would put my hand in the tank, come up to me, do his little dance, then procede to try and "clean" my arm. It felt a little bizarre lol!