Bristleworm debate

[Blom]

I was feeding the tank last night when I saw a Bristleworm pop out of the live rock. I would venture to guess it was about a 1/4" in width and had to be close to 6+ inch long. White in color, with hints of red and white bristles. In a short amount of reading last night about them I found just about every opinion one could have. Keep them, keep them only if there small, don't keep them. From the articles many said they are mainly scavengers, with only a few different species actively hunting. But all agreed that the larger they get the more of an issue they can be. Just wanted to see what others opinions are on the site about them, and if there have been any negative experiences with them. My concern is he has grown quite big in a small amount of time, and this is only in a 28G cube.