i love this feeder and so do the birds.
i used to have a standard tube feeder but there was so much wastage as seeds fell to the ground but not with this feeder. its clean, sturdy and easy to use. yes it took the birds a while to get use to it but they feed very happily now and i get a wide variety of birds using it. they queue up in a nearby tree waiting their turn to feed.
i notice some people have commented on the stopper not being a good fit. what you have to do is put the stopper in it hole the give it an extra little push and it snaps tightly and happily into place so the ball is totally water tight.
please give this a go, it really is fab