Mine has grown from 3.5" to a very stocky 5.5" and is very interactive. He is now by far the most interactive fish I have and recognizes me and reacts to me differently than other people who approcach the tank. I love how it's so bulky and even its sporadic 'bad' attitude. It's also a favorite of my wifes, especially the red eyes. I'm hoping in a few months he will even let me pet him 
He used to be really aggressive when smaller, but now he's catching up to the other fish in size, he's mellowed out quite a bit. Bad picture during weekly cleaning but here is a shot of him with some of the other fish:
He used to be really aggressive when smaller, but now he's catching up to the other fish in size, he's mellowed out quite a bit. Bad picture during weekly cleaning but here is a shot of him with some of the other fish: