You can easily stack them four high, fully loaded. I routinely placed mine in the bottom of large cargo bags, and they often stood up under loads in excess of 150 pounds. I have used them for long term storage quite successfully - I have one parked under the bushes right now loaded with supplies which is doing quite well.

I have observed that the red handles do fade with long term exposure to sunlight, but so far that hasn't affected their utility.

I was confident that they were mouse proof after considerable experience storing food within while in camp. Then on one trip I found a neat hole nibbled in one; I think what happened is that a mouse got inside when the lid was off and he gnawed his way to freedom.

In my experience, ActionPackers have been the most satisfactory container I have come across. Their rigidity provides protection for the contents, something not as likely with a drybag. I would agree with Art's drybag comments earlier in this thread. On most of my trips I used both APs and dry bags, both to good effect.