I tasted the Crimson Topaz apple today from a tree in my nursery. It seems a worthy tart apple for those seeking scab resistance.
It has some of that "big cell" crunchiness and the juiciness of Honeycrisp but with a real acid kick. It's supposed to ripen in early Oct according to Adam's, which probably means mid-Oct here and apples looked ready a couple of weeks ago. I tried one then but the one today was more fully flavored so it doesn't seem to easily turn to mush.
I like it better than Liberty for sure and would consider it worth growing even without the disease resistance. It was growing right next to a Jonagold whose apples were almost twice the size. I prefer the smaller size as the Jonagolds are too much to eat in one apple meal. I expect Topaz to size with liberty.
Adam's is sold out for next season and I don't know who else carries it.