That is the one I have been going by.
All of the chicks that were totally black were females. When they grew up they look a lot like a black star in that they had some brown/gold ticking in the neck. Egg color was really good on them so I am thinking with the next (F2) the egg color will improve even more. It will be interesting to see how they sex out in this F2 cross. I know you cull all of the solid colored birds and keep only the barred. I have two lines started one of a commercial barred rock and on in my heritage barred rocks. The Heritage look really good but are still really young and the commercials are good but finding them to be a lot more flighty than what I thought they would be. Time will tell about the personality of the Heritage chicks.