Personally, whenever I'm in game, I get more questions about why my name is differently coloured, and why I have a weird symbol in from of my name than anything else. Having the colour and symbol forces new players to interact with me, and then I can explain who I am and what I do. It lets me greet new players and have them view me as a higher up, instead of a regular player.
I think if I had the blatant "hey I'm staff!", no one would ever talk to me. Let's be honest here, when was the last time you walked up to any sort of staff anywhere, without knowing them, and tried to initiate a conversation with them? Having beginners ask what we are shows the, that even though we're staff, we're still friendly and like to be talked to.