The question I get most about stackable boxes is whether they actually stack once you've filled them, or whether that's a lie the packaging tells you in the store. Honest answer: with the cheap ones, no, not once there's any weight in there, the walls bow and the lid stops sitting flat. With a good set, yes, even six or seven high, because the walls are stiff enough to hold their shape and the lids are built to carry load, not just keep dust off.
These earn their place in closets, under beds, in attics and garages, basically anywhere you're fighting for vertical space instead of floor space, which in my experience is most rooms in most houses that aren't enormous. They're good for off season clothes, kids' outgrown stuff you're not ready to let go of, holiday decorations, paperwork you're required to keep but never look at. Clear ones are better for anything you'll need to find again without opening four boxes first, solid colored ones are fine for stuff you only dig out once a year. Where they don't belong is anywhere they'll be on permanent display in a living space, a stack of plastic bins next to the couch reads like you're mid move even if you moved in three years ago, and they don't do well outside either, sun makes cheap plastic brittle and the lids warp in heat.
The stuff worth checking before you buy, or the day they show up, is the lid fit and the wall thickness. Press on the side of an empty one in the store, if it flexes like a yogurt tub, it'll sag under real weight and the stack leans within a month. Check that the lids actually lock or at least seat with a proper lip, not just balance on top, because that's the difference between a stack that survives a closet door swinging open and one that dumps itself on your foot. If you're buying a set meant to nest when empty, make sure they actually nest, some ranges claim it and the taper is wrong by a few millimeters and they just sit there unstacked and sad. Also check the handles don't crack when the box is full and cold, which happens more than you'd expect with winter storage in a garage.
The detail that makes a good set a pleasure is when the lids are snug enough that you can pick up the whole stack by the top handle and nothing below it shifts.