I ordered from Efowl about 15 years ago. I ordered straight run and the male / female ratio was about fifty percent. This summer I decided to get back into raising chickens. I have ordered twice this year from Murray McMurray. I chose them because they are the oldest hatchery in the country, having started in 1917. Hatcheries are notorious for poor inbreeding practices (whether they deserve that reputation or not, it seems to be a consensus.) It seems to me that the hatchery with the most experience is more likely to use good breeding practices, if for no other reason than having learned the hard way if they had ever tried to cut corners in the past.
I ordered 18 pullets and 6 cockerels back in July (day-old chicks), and again in September. Both times the sexing was right. The ones from September are only about six weeks old now, but they are Buff Orpingtons, easy to sex at this age when you see a cockerel and a pullet side by side. I am glad that I ordered a few extra males. Hatcheries don't really breed towards the "breed standard" so the chicks will vary. At least that was the case with my Speckled Sussex. I'm no show bird breeder, but out of those six roosters I have one that looks enough like a proper Specked Sussex to be a breeder in my SS plan. One in particular strays pretty far from the standard, but he is so cool and beautiful that he will be part of my "forget the standard" breeding plan!
McMurray also throws in a free rare chick with each order if you want it. My first rare chick turned out to be a Cuckoo Marans. The second was a Blue Andalusian. They don't tell you what the breed is. You have to dig through the rare breeds section of their online catalog and watch chick videos to compare their appearances, then watch the chicks grow and see if you guessed right. It's actually pretty fun. I will warn you though, this is a clever scheme. It worked on me. I now have plans to order more Cuckoo Marans and Blue Andalusians!