I agree that it sorta depends on what you do. The rules are changing about Tattoos. They are more widely accepted, but some of the old school guys still frown upon them. My father hates tattoos and is pissed that I have one. He often comments about people's visible tattoos. I think that he does it, just to get under my skin. He is the reason why I would hesitate to get anything really visible. Did I mention that he is my boss?
Having said that, I have been itching to turn my armband into a 1/4 sleeve with coverage on the shoulder. I just cannot decide what I want.
Lastly, I do feel that a full sleeve does look unprofessional in a formal work environment. I work in a semi-formal business environment. So, visible tattoos would be frowned upon. If I was a surf-shop owner or in a laid back business, I would probably have a full sleeve myself.