JF,
I agree, it's hard to tell if there isn't some squamosa blood in there....but either way I hear the tree is more cold hearty than any common atemoya (withstanding 20F when mature), and fruits set without hand pollination...and taste amazing!
I've heard lots of respectable people, saying good things about this cultivar...so I know it's a winner already!
I will make sure to report when I finally taste the fruits!