i haven't eaten them yet, uli, only seen the mention on that one site
i have tasted a few from the tree we have, i always forget what the species is--a commonly grown european here, i have never heard of people using them, but in the countryside, the birds clean them very fast! the berries i tried were sour but tasty, like cornus sericea.. i've acquired a bit of a taste for many of these bitter berries, though in very small doses.. i guess otherwise you'd need to add sugar/cook them, combine with others etc..
perhaps the site i quoted was talking about a particular cultivar....