I use some of those exact tubs as well. They work great for slings that are outgrowing delicups. The fact that they are very stackable doesn't hurt anything at all!

Very nice setups! I'm sure your guys are digging their new living quarters. I'd suggest getting a soldering iron to make your ventilation holes from now on though. You won't believe how much easier, faster and neater they are. Just wear a mask when you go to burn the holes.