I had to upgrade to a bigger box.
http://www.bunchobikes.com/toolbox.jpg That's about 12' of stainless on top. Didn't realize how many tools I had until I ended up filling all the drawers! My old green Mac is to the left. Went from a triple bank to a five bank. The biggest Snapon makes. And I can still add top boxes, lockers and hutches if I want. But I probably won't. Maybe just one hutch on one side. They are nice for locking stuff in when you don't have time to put it all away!
As for Craftsman, we got a couple of their big industrial boxes for the shop's heavy tools. Within a week, one of the drawers had ripped away from the mounting. We'll have to get in there one of these days to fix it. I have one of the professional series box risers on my work truck. I'm not real impressed with the lock mechanism. One tug on the drawer and it can be easily opened, bending the lock tab. Other than that, the ball bearing sliders are real nice. Drawers could be deeper. Less fluff, more storage would help, too!