Though more often enjoyed by our resident squirrel couple, our birds (given the chance to get a beak in edgeways) love these we have three feeders out with these, one for the squirrels (as they refuse to go for easy options) and two for the birds.
We even had a woodpecker and though woods are not that far away, just down the hill, we certainly didn't expect a visit from this though we used to, obviously we weren't providing the correct thing(s) for that visitor, certainly something to get when doing a bird count never know what you might miss without.