We thought these would be a good idea but first, the hose connections do not allow for the water to fully drain and because the down spout sits above the wire drain entry point they became a haven for mosquitos.  Secondly, we live in a place where it rains a fair amount during a storm so they fill up very quickly and then overflow.  It is not possible to plant anything in the top because of this and we need to have a hose attached constantly to drain the water during a rain.