I am in Europe, and have fruited about 12 seedling trees that I grew of seeds I got from Skillcult’s crosses in 2018 and 2019.
I have made a video about the best finds among them, and among some of my own seedlings and crosses:
I would say the success rate of finding surprisingly good apples among his crosses is high: about 1/4 are keepers for me, 1/2 is just as good as any other apple and 1/4 is too small, hard, bitter, mealy or has another trait that would let you gladly let go of the tree.