I don't know that I've seen a 10X anything... or that I'd recognize a bad foot if I saw it - unless it was something like a screw-claw or elf-slipper(founder) kind of deal.
That said, here are a couple of comments I've seen on another board, from Angus breeders; take it or leave it:
One from KS: "I have seen a ton of 10X calves over the past few years and I have never seen a bull that can consistently produce such putrid rear wheels. You can pick them out simply by the rear leg and feet structure.
I could never stand MIF and 10x seems to be worse."
One from IA: "I've got a few 10X daughters coming with their second calf. If I had to describe them in one word it would be nondescript, with the exception of fertility. Fertility was above average, all settled first service AI and bred back for second calves early, even one that had twins. Otherwise I can't really complain or promote them. Bulls were a little more high headed than I like, cows seem to be OK."
Another one from IA: "Ten X feet were unacceptable here so good luck."