To a first and second approximation, no one in America has ever eaten an Antonovka. But strangely, it's also one of the more common apples planted in America! The explanation for this apparent contradiction is that Antonovka is one of the most common "standard" (ie, full size) apple rootstocks. So they are planted, but almost never allowed to fruit. Instead, the tops are chopped off and a different apple is grafted on top as a replacement.

They are used as rootstock because they are deep rooted, drought tolerant, and very cold hardy. Conveniently, Antonovka are also one of the few apple varieties that tends to grow true from seed. This makes propagating them as rootstock much easier, since it's very fast and easy to plant seeds rather than making clones. Here's an article that talks up the use of Antonovka as a rootstock: http://www.kuffelcreekapplenursery.com/rootstocks.htm.

I've got 20 Antonovka ordered for next spring that I'm planning to graft to. Perhaps I should leave one whole and see what it produces --- like most Americans, I've never eaten one.