Hanging the tree upside down is a new fad. It would let the ornaments hang better and allow better access under or near the tree. But it just seems weird. I don't know the mechanics of how it's done.
We go with an artificial tree because it takes my wife forever to hang ornaments, and then forever to take them down. The thing is in our family room for at least six weeks. Can't do that with a real tree. Needles would all fall off.