My experience with E. Pungens is from my sister's patch in GA. She has
dozens of plants. The fruit is quite edible, tasty, similar to other
illeagnus in that it can be astringent, but looses that astringency when
fully ripe. The weakness of Pungens (apart from invansiveness) is that
they set fruit sparsely, perhaps unreliably (?) as you go further north.
It seems like my sister's bushes are fairly reliable, but she is zone
8B, very warm. My experience with E. Pungens is that the flavor is
similar to autumn olive or goumi, but perhaps a bit less tart when fully
ripe. Autumn olives are especially heavy fruiters (and VERY invasive),
goumis set pretty heavily as well. I have never seen Pungens set as
heavily as other illeagnus, but I do not have a lot of experience with
it either.
Alexis