Knock on wood, but 18 months later, we still have all 12 chickens that we ordered from Cackle. They have been good, productive layers up to now, when they are going through their first molt, and are well tempered with us and each other. I have noticed some trends here with regard to the type of chickens ordered, I think. We have barred rock, NH Reds and Speckled Sussex, and I think Cackle is strong in those breeds. Our BR lay just huge eggs, beyond jumbo. Sometimes they don't fit in the carton. I also had occasion to call customer service during the ordering process (They sent a note saying that they didn't have what we had ordered for that date, and I needed to negotiate an alternative) and while it took a couple calls, everything was resolved satisfactorily and I got exactly what we had agreed on. Our chicks arrived healthy and peeping, in very cold weather.
We had ours immunized against Mareks, which I recommend, and we always treat prophalactically with Corid before putting them outside or earlier if they show signs of Coccidiosis. Important to keep Corid on hand!
Oh and regarding sexing: we ordered pullets, and didn't get a single roo. I was impressed at that; our prior feed store "pullets" had been about half male.