I know of (and have read) of a tendency for the boys to feather out slower than the girls. It was true with my roos.
Not that the girls don't also go thru the ugly half-bald stage, just that the boys take longer to feather out.
ETA: Here's the criteria I used with my chicks with 100% accuracy. Granted it probably helped that I had all of one breed to compare:
According to UC Davis Veterinary Care Program.
2. Physical Characteristics (4-6 weeks of age)
a. Comb The cockerels comb is medium size and pinkish, the pullets is small and yellowish.
b. Legs The cockerels legs are sturdy and long, the pullets are finer and shorter.
c. Tail The cockerels tail is stumpy and curved, the pullets is longer and straight.
d. Back The cockerel has a thin line of stub feathers down the center of his back, the pullet has more advanced feathering along the center of her back.
e. Side of neck, flank and crop The feathering in the cockerel in these areas is poorly advanced, the pullets feathering in these areas is well advanced.
f. Wing bows In the cockerel the wing bows are bare, in pullets the wing bows are covered with small feathers.