I picked up a group of 8 at last year's ACA so I've had them just short of a year. Largest is now about 9". Just recently pulled a pair that seem to be getting along and placed them within their own 75g. Here are a few pics:
They can really hold their own. For what was only going to be for a day, I added one hog to a group of rather ticked off, young adult A. chanchos, and while the hog is a bit larger/older, he is still the dominate fish in that group.