I made the mistake of getting one...
Unfortunately, the lfs didn't tell me that they get the size of a basketball- now, I have a 55 gal, and he is the size of a very large softball... needless to say, you need to be very careful when cleaning the thank. I have been poked (1 time) and it went down to the bone of my thumb. Hurt for about 4 days. In retrospect, I wouldn't have gotten him. I'm thinking of returning him to the store now that he's getting so big.