Sandbox is broader for me. No mini-adventures, just a bunch of maps, tons of NPCs with their households, goals, holdings, etc., monster lairs (but not like mini-adventures again to be clear), and lots of detail on what is going on. But little direction as to what the PCs should do, and the expectation that this will all fall apart as the PCs interact with it.
It sound like DH has some of that but hasn't got the freedom that usually has, or the flexibility, so is more of a "Bioware" design. Nothing wrong with that but will suck if you expected a linear AP.